–What do you often do ________ classes to relax?
–Listen to music or walk around the school.
A. over B. through C. between
While we _________, we saw a UFO land on a street.
| A．were shopping | B．shopped | C．are shopping | D．shop |
—Would you mind my smoking here?
—_________. No smoking here.
| A．Oh, please don’t | B．Yes, please. |
| C．Of course not | D．It doesn’t matter |
There isn’t going to be any pollution in the future, _________?
| A．be there | B．be not there | C．is there | D．isn’t there |
— Would you like some butter with your bread?
— ____________.
| A．Not at all |
| B．OK. Here you are |
| C．That is right. |
| D．Yes, a little, please |
It has been two years _________ he came to China.
| A．since | B．after | C．before | D．till |