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 37 to 43.
A team of Russian scientists has challenged the theory that the woolly mammoths became extinct 10,000 years ago at the end of the Ice Age. The scientists have reported that the beasts may have survived until 2000 B.C. on an island off the coast of Siberia, where researchers uncovered 29 fossilized woolly mammoth teeth ranging in age from 4,000 to 7,000 years. The question to be asked now is, how did these prehistoric pachyderms survive in their island environment? One possibility is that they adapted to their confined surroundings by decreasing their bulk. This theory is based on their smaller tooth size, which has led scientists to believe that they were only 6 feet tall at the shoulder compared with 10 feet of their full-sized counterpart. But would this be enough to enable them to survive thousands of years beyond that of other mammoths? Researchers are still working to uncover the reasons for this isolated group's belated disappearance.
According to the scientists, the woolly mammoths may have managed to survive because they
A. shed their hair
B. grew smaller teeth
C. became herbivores
D. decreased in size
Đáp án D
Dụa theo các nhà khoa học, voi ma mút lông xoăn có lẽ đã sống sót bởi vì ______
A. rụng bớt lông
B. mọc răng nhỏ hơn
C. trở thành loài ăn cỏ
D. giảm về kích cỡ
Giải thích: “This theory is based on their smaller tooth size, which has led scientists to believe that they were only 6 feet tall at the shoulder compared with 10 feet of their full-sized counterpart.” (Lý thuyết này dựa vào cỡ răng nhỏ của voi ma mút, cái mà đã làm cho các nhà khoa học tin rằng chúng chỉ cao 6 feet tại vai so với 10 feet của voi tổ tiên.) => giảm từ 10feet xuống còn 6feet