单项选择题

（）is known to us all is that the Chinese government has spared no efforts to protect people from fake food.

A.What
B.It
C.That
D.As

点击查看答案&解析

单项选择题

A.the；an
B.a；the
C.a；an
D./；a

单项选择题

—Has Tom finished his homework yet?
—I have no idea;he（）it this morning.

A.did
B.had been doing
C.had done
D.was doing