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
网友回答
A. showed
B. has shown
C. will show
(答案→)D. is showing
解析：考查时态。“几年前，我不知道这件事，但最近的科学正在表明，睡眠不好的人容易得病。”用进行时