–Where _______ the socks?   --_______ on the bed.

The population of China___ to many times what it was in 1949, and most of its population ___ farmers.

The government’s efforts to cut the homework burden of primary and middle school students _____ mixed reactions(反应).

There are usually 28        in a person’s mouth, so we should listen to the doctor’s ______ to protect（保护）them.

 In the office I never seem to have time until after 5:30 pm, _____ many people have gone home.