Mark the letter A, B, C, or D on your answer sheet to indicate the word or phrase that is OPPOSITE in meaning to the underlined part in each of the following questions.
Population growth rates vary among regions and even among countries within the same region.
A. remain unstable
B. fluctuate
C. restrain
D. stay unchanged
Đáp án : D
“vary”(v): thay đổi, biến đổi. Trái nghĩa là “stay unchanged” (giữ nguyên)