Listen! Tom is singing in the next room.–It _______ be Tom. He has gone to Shanghai.

What do you want to do for vacation?—I ____ my aunt.

______evening, Robert kept playing games on the computer.

I don’t want to make friends with those people ______ think of themselves first when in trouble.

Some volunteers from Beijing arrived in Shanghai _____ April 29 to work for the World Expo. [ ]