ngày THI ĐẤU OLM tối nay, ngày 28/04/2023 để so tài với học sinh toàn quốc!!!

Ôn tập kiểm tra học kì 2 hiệu quả, đạt thành tích cao!

K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

Tất cả Toán Vật lý Hóa học Sinh học Ngữ văn Tiếng anh Lịch sử Địa lý Tin học Công nghệ Giáo dục công dân Âm nhạc Mỹ thuật Tiếng anh thí điểm Lịch sử và Địa lý Thể dục Khoa học Tự nhiên và xã hội Đạo đức Thủ công Quốc phòng an ninh Tiếng việt Khoa học tự nhiên
Mua vip
LQ
Lê Quỳnh Anh
1 tháng 3 2017

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.

The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house, the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57, 600 pounds. The pressure on the four walls adds up to 172,800 pounds.

If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the enormous inside pressure may cause the building to burst.

Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect their property. This may cause far worse damage later. For the same reason, tornado cellars must have an air vent. Otherwise, the cellar door might be blown out when a tornado passes over it.

According to the passage, tornadoes can destroy buildings because the ________.

A. force of a tornado increases the air pressure in a building

B. air pressure at the center of a tornado is over 172,000 pounds

C. weight of a tornado can crush a building's roof when it passes overhead

D. air pressure inside a tornado is less than the air pressure inside a building
#Mẫu giáo
1
DH
Dương Hoàn Anh
1 tháng 3 2017

Đáp án D

Thông tin trong bài “This explosion is caused by the low air pressure at the center of a tornado” à áp suất không khí ở bên trong một cơn lốc xoáy thấp hơn áp suất không khí ở bên trong tòa nhà.

 

Đúng(0)
LQ
Lê Quỳnh Anh
10 tháng 12 2019
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.The pressure at the center of a tornado is usually 13 pounds per square...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.

The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house, the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57, 600 pounds. The pressure on the four walls adds up to 172,800 pounds.

If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the enormous inside pressure may cause the building to burst.

Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect their property. This may cause far worse damage later. For the same reason, tornado cellars must have an air vent. Otherwise, the cellar door might be blown out when a tornado passes over it.

In line 2, the word "funnel" refers to which of the following?

A. A bomb

B. A house

C. A tornado

D. An explosion
#Mẫu giáo
1
DH
Dương Hoàn Anh
10 tháng 12 2019

Đáp án C

Dựa vào thông tin “Sometimes, as the writhing, twisting funnel passes over a house, the wall and ceiling burst apart as if a bomb had gone off inside” (đôi khi, như một cái phễu xoáy quàn quoại đi qua một ngôi nhà, những bước tường và trần nhà bị vỡ tung ra như thể có một quả bom vừa nổ ở bên trong) à từ “funnel” đề cập đến đối tượng “a tornado”.

Đúng(0)
LQ
Lê Quỳnh Anh
10 tháng 5 2019
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.The pressure at the center of a tornado is usually 13 pounds per square...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.

The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house, the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57, 600 pounds. The pressure on the four walls adds up to 172,800 pounds.

If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the enormous inside pressure may cause the building to burst.

Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect their property. This may cause far worse damage later. For the same reason, tornado cellars must have an air vent. Otherwise, the cellar door might be blown out when a tornado passes over it.

According to the passage, people close their windows to prevent damage caused by ________

A. tornadoes

B. thunderstorms

C. uprooted trees

D. bursting structures
#Mẫu giáo
1
DH
Dương Hoàn Anh
10 tháng 5 2019

Đáp án B

Thông tin “Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect their property” à mọi người thường đóng cửa sổ để ngăn chặn những sự phá hủy gây ra bởi những cơn giông bão

Đúng(0)
LQ
Lê Quỳnh Anh
17 tháng 9 2018
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.The pressure at the center of a tornado is usually 13 pounds per square...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.

The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house, the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57, 600 pounds. The pressure on the four walls adds up to 172,800 pounds.

If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the enormous inside pressure may cause the building to burst.

Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect their property. This may cause far worse damage later. For the same reason, tornado cellars must have an air vent. Otherwise, the cellar door might be blown out when a tornado passes over it.

Which of the following is the main topic of the passage?

A. How tornadoes can be prevented

B. When tornadoes usually occur

C. Where tornadoes are formed

D. Why tornadoes cause so much damage
#Mẫu giáo
1
DH
Dương Hoàn Anh
17 tháng 9 2018

Đáp án D

Đoạn văn hầu như đề cập đến những tác hại cũng như những đặc điểm gây hại của lốc xoáy à đáp án D phù hợp nhất với nội dung của bài (chủ đề chính của đoạn văn là “Tại sao lốc xoáy lại gây ra những sự phá hủy nghiêm trọng”)

Đúng(0)
LQ
Lê Quỳnh Anh
10 tháng 4 2017
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.The pressure at the center of a tornado is usually 13 pounds per square...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.

The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house, the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57, 600 pounds. The pressure on the four walls adds up to 172,800 pounds.

If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the enormous inside pressure may cause the building to burst.

Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect their property. This may cause far worse damage later. For the same reason, tornado cellars must have an air vent. Otherwise, the cellar door might be blown out when a tornado passes over it

In line 16, the word "it" refers to ________

A. wind

B. hail

C. cellar door

D. air vent
#Mẫu giáo
1
DH
Dương Hoàn Anh
10 tháng 4 2017

Đáp án C

Thông tin trong bài “the cellar door might be blown out when a tornado passes over it” (cửa hầm chứa đồ có thể bị thổi bay ra khi một cơn lốc xoáy đi qua nó) à đại từ “it” chính là đề cập đến danh từ “cellar door”

Đúng(0)
LQ
Lê Quỳnh Anh
30 tháng 12 2018
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.The pressure at the center of a tornado is usually 13 pounds per square...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.

The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house, the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57, 600 pounds. The pressure on the four walls adds up to 172,800 pounds.

If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the enormous inside pressure may cause the building to burst.

Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect their property. This may cause far worse damage later. For the same reason, tornado cellars must have an air vent. Otherwise, the cellar door might be blown out when a tornado passes over it.

According to the passage, what is the difference per square inch between the air pressure inside a building and the air pressure inside a tornado?

A. 2 pounds

B. 10 pounds

C. 13 pounds

D. 15 pounds
#Mẫu giáo
1
DH
Dương Hoàn Anh
30 tháng 12 2018

Đáp án A

Thông tin được nhắc đến trực tiếp trong bài “The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much” à sự khác nhau giữa áp suất không khí ở trong một tòa nhà và ở trong một cơn lốc xoáy là 2 pound mỗi inch vuông.

Đúng(0)
LQ
Lê Quỳnh Anh
6 tháng 5 2019
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.The pressure at the center of a tornado is usually 13 pounds per square...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 36 to 42.

Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado.

The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house, the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57, 600 pounds. The pressure on the four walls adds up to 172,800 pounds.

If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the enormous inside pressure may cause the building to burst.

Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect their property. This may cause far worse damage later. For the same reason, tornado cellars must have an air vent. Otherwise, the cellar door might be blown out when a tornado passes over it.

According to the passage, the pressure on a building during a tornado can be relieved by ________.

A. closing the cellar

B. opening the windows

C. using a fan for ventilation

D. strengthening the roof and walls
#Mẫu giáo
1
DH
Dương Hoàn Anh
6 tháng 5 2019

Đáp án B

Dựa vào đoạn “If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building” à áp suất trong một tòa nhà trong suốt trận lốc xoáy có thể được giải phóng bằng cách mở cửa sổ

Đúng(0)
LQ
Lê Quỳnh Anh
10 tháng 8 2019
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.   Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

  Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

  As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

  Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

  To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

What does the passage mainly discuss?

A. How to prepare for a deep dive 

B. The effect of pressure on gases in the human body. 

C. The equipment divers use 

D. The symptoms of nitrogen bubbles in the bloodstream
#Mẫu giáo
1
DH
Dương Hoàn Anh
10 tháng 8 2019

Chọn B

Bài đọc chủ yếu thảo luận về vấn đề gì?

A. How to prepare for a deep dive: Cách chuẩn bị cho một chuyến lặn sâu

B. The effects of pressure on gases in the human body: Tác động của áp lực lên không khí trong cơ thể con người.

C. The equipment divers use: Thiết bị mà thợ lặn sử dụng

D. The symptoms of nitrogen bubbles in the bloodstream: Dấu hiệu khi bóng Ni tơ ở trong dòng chảy của máu.

Dẫn chứng: “Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure” (Trong một số trường hợp nhất định, cơ thể con người phải đối phó với các khí ở áp suất khí quyển lớn hơn bình thường)

Đúng(0)
LQ
Lê Quỳnh Anh
30 tháng 6 2017
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow. Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

 

What does the passage mainly discuss?

A. How to prepare for a deep dive

B. The effect of pressure on gases in the human body

C. The equipment divers use

D. The symptoms of nitrogen bubbles in the bloodstream
#Mẫu giáo
1
DH
Dương Hoàn Anh
30 tháng 6 2017

Đáp án B

Bài đọc chủ yếu thảo luận về vấn đề gì?

A. How to prepare for a deep dive: Cách chuẩn bị cho một chuyến lặn sâu

B. The effects of pressure on gases in the human body: Tác động của áp lực lên không khí trong cơ thể con người.

C. The equipment divers use: Thiết bị mà thợ lặn sử dụng

D. The symptoms of nitrogen bubbles in the bloodstream: Dấu hiệu khi bóng Ni tơ ở trong dòng chảy của máu.

Thông tin ở câu chủ đề của đoạn: “Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure” (Trong một số trường hợp nhất định, cơ thể con người phải đối phó với các khí ở áp suất khí quyển lớn hơn bình thường)

Đúng(0)
LQ
Lê Quỳnh Anh
13 tháng 6 2018
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow. Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

 

It can be inferred from the passage that which of the following presents the greatest danger to a diver?

A. Pressurized helium 

B. Nitrogen diffusion 

C. An air embolism 

D. Nitrogen bubbles 
#Mẫu giáo
1
DH
Dương Hoàn Anh
13 tháng 6 2018

Đáp án C

Có thể suy ra từ bài đọc rằng điều gì là mối nguy hiểm lớn nhất đối với thợ lặn?

A. Pressurized helium: Khí Heli nén

B. Nitrogen diffusion: Sự khuếch tán khí Nitơ

C. An air embolism: Sự thuyên tắc hơi

D.Nitrogen bubbles: Bóng khí Nitơ

Thông tin ở đoạn cuối, dòng thứ nhất. “During ascent from a depth of 10 meters, the volume of air in the lung will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.” (Trong quá trình nồi lên từ độ sâu 10 mét, lượng không khí trong phổi sẽ tăng lên gấp đôi vì áp lực khí tại bề mặt nước chỉ còn 1 nửa so với ở độ sâu 10 mét. Sự thay đổi về lượng khí có thể làm phổi sưng phồng, thậm chí là vỡ nát. Hiện tượng này gọi là thuyên tắc hơi.) 

Đúng(0)
Bảng xếp hạng
Tất cả Toán Vật lý Hóa học Sinh học Ngữ văn Tiếng anh Lịch sử Địa lý Tin học Công nghệ Giáo dục công dân Âm nhạc Mỹ thuật Tiếng anh thí điểm Lịch sử và Địa lý Thể dục Khoa học Tự nhiên và xã hội Đạo đức Thủ công Quốc phòng an ninh Tiếng việt Khoa học tự nhiên
  • Tuần
  • Tháng
  • Năm
Các khóa học có thể bạn quan tâm
Tổng thanh toán: 0đ (Tiết kiệm: 0đ)
Tới giỏ hàng
Yêu cầu VIP