Your classroom is so clean. —Of course. It ______ every day.

It was getting harder and harder ___ money for the poor kids, because the price(物价) kept_____,

______Jim ______his cousin has been to America, but to our surprise, _______of them know the country well.

Would you please not smoke here Look at the sign. —- ________.

ery tired, helping with theclothes.—-Why not take a rest,then—– ________.