Years ago we didn’t know this but recent sciencethat people who don’t sleep well soon ge

问题补充：

Years ago we didn’t know this , but recent sciencethat people who don’t sleep well soon get ill.

A. showed

B. has shown

C. will show

D. is showing

答案：

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