Two pages of the original manuscript (底稿) of Albert Einstein’s GeneralTheory of Relativity were________ on display in the Israel Pavilion ofthe 2010 World Expo in Shanghai.

There’ssomeone knocking on the door. Who _____it be?— It must be Mary. She promised to be here at 8：00.

_______is great fun. It can make us happy.

The boss said we had only three days to finish the work.Don’t worry. We have already ____? two thirds of it.

Do you think he will have dinner with us tomorrow—I’m not sure. He come if he has time.