题目内容
Years ago we didn't know this, but recent science ______ that people who don't sleep well soon get ill.
A. showed B. has shown C. will show D. is showing
B
解析:
考查动词的时态。根据句子中的recent science可以知道句子中“含有过去发生的动作”对现在产生的影响。所以答案应该用现在完成时。
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