一Did they take any photos? 一______．
| A．No，they didn't | B．No，they did |
| C．No，they aren't | D．No，they weren't |
—Our school is beautiful!
—It will be more beautiful if more trees and grass _____ by us.
A. plant B. is planted C. are planted
—I have worked hard at math, but it seems that I haven’t made any progress.
—Keep on _____ at it, and you will be successful.
A. work B. working C. to work
—This physics problem is too difficult. Can you show me _____, Wang Li?
—Sure.
A. what to work it out B. what to work out it C. how to work it out
In the past, the workers _____ do a lot of hard work.
A. forced B. forced to C. were forced to
I’m afraid I have to _____ the doctor’s advice.
A. follow B. receive C. carry