We had fun ________ the robots do many different kinds of things.
A. to watch B. watched C. watching D. watches
The boss makes the workers ________ long hours every day.
A. work B. to work C. works D. working
—________ will you come back from your work, Dad?
—In about half an hour, dear.
A. How long B. How often
C. What time D. How soon
There _______an important meeting this afternoon. All of you should attend it.
A. will have B. will be C. will hold D. has
There are three ________ students in their school.
A. thousands of B. thousand of
C. thousands D. thousand
It’s polite ________ the old. We should learn from you.
A. of you to help B. for you to help
C. of you helping D. for you helping
