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 43.
The hard, rigid plates that form the outermost portion of the Earth are about 100 kilometers thick. These plates include both the Earth's crust and the upper mantle. The rocks of the crust are composed mostly of minerals with light elements, like aluminum and sodium, while the mantle contains some heavier elements, like iron and magnesium. Together, the crust and upper mantle that form the surface plates are called the lithosphere. This rigid layer floats on the denser material of the lower mantle the way a wooden raft floats on a pond. The plates are supported by a weak, plastic layer of the lower mantle called the asthenosphere. Also like a raft on a pond, the lithospheric plates are carried along by slow currents in this more fluid layer beneath them.
With an understanding of plate tectonics, geologists have put together a new history for the Earth's surface. About 200 million years ago, the plates at the Earth's surface formed a “supercontinent” called Pangaea. When this supercontinent started to tear apart because of plate movement, Pangaea first broke into two large continental masses with a newly formed sea that grew between the land areas as the depression filled with water. The southern one — which included the modern continents of South America, Africa, Australia, and Antarctica — is called Gondwanaland. The northern one — with North America, Europe, and Asia — is called Laurasia. North America tore away from Europe about 180 million years ago, forming the northern Atlantic Ocean. Some of the lithospheric plates carry ocean floor and others carry land masses or a combination of the two types. The movement of the lithospheric plates is responsible for earthquakes, volcanoes, and the Earth's largest mountain ranges. Current understanding of the interaction between different plates explains why these occur where they do. For example, the edge of the Pacific Ocean has been called the “Ring of Fire” because so many volcanic eruptions and earthquakes happen there. Before the 1960's, geologists could not explain why active volcanoes and strong earthquakes were concentrated in that region. The theory of plate tectonics gave them an answer.
According to the passage, the lithospheric plates are given support by the
A. upper mantle
B. ocean floor
C. crust
D. asthenosphere
Đáp án D
Thông tin: Together, the crust and upper mantle that form the surface plates are called the lithosphere … The plates are supported by a weak, plastic layer of the lower mantle called the asthenosphere.
Dịch nghĩa: Cùng với nhau, lớp vỏ và lớp manti trên tạo thành các mảng bề mặt được gọi là thạch quyển ... Các mảng được hỗ trợ bởi một lớp nhựa yếu của lớp manti dưới gọi là quyển mềm.
Như vậy phương án D. asthenosphere là phương án chính xác nhất.
A. upper mantle = lớp manti trên
B. ocean floor = đáy đại dương
C. crust = lớp vỏ Trái Đất