—Ben and Sue aren’t home,are they?
—No.They _____to London on business.
| A．have gone | B．go | C．have been | D．will go |
There are lots of _____that students have to follow in school.
| A．exercises | B．problems |
| C．skills | D．rules |
Fresh food is good for you . But you have to ______it first because sometimes it a little dirty.
| A．taste | B．smell | C．wash | D．plant |
Ther will be less pollution ___more people use public transportation .
| A．but | B．though | C．unless | D．if |
Our teacher was very happy because _____failed the examination.
| A．somebody | B．nobody |
| C．anybody | D．everybody. |