Mark the letter A, B, C, or D on your answer sheet to indicate the word (s) OPPOSITE in meaning to the underlined word(s) in each of the following sentences
Population growth rates vary among regions and even among countries within the same region.
A. restrain
B. fluctuate
C. remain unstable
D. stay unchanged
Đáp án : D
Vary = thay đổi đa dạng, phong phú. Stay unchanged = duy trì, không thay đổi