Years ago we didn't know this, but recen
题型:选择题
问题:
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
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