Air pollution, together with littering, ____ many problems in our large industrial cities today.
| A．causes | B．cause | C．caused | D．causing |
She is believed______ the train, otherwise she would have arrived here by now.
| A．to miss | B．to have missed | C．to be missed | D．to be missing |
Scientists say it may be five or six years ______ it is possible to test this medicine on human
patients.
| A．since | B．after | C．before | D．when |
The victims of the accident demanded that the case ______ at once.
| A．would be looked into | B．should look into |
| C．be looked into | D．look into |
We each took ______ tea after having ______ wonderful supper at my aunt’s yesterday.
| A．a; / | B．/; / | C．the; the | D．a; a |
The dress is nice but she doesn’t like the ______ on the material.
| A．shape | B．pattern | C．size | D．model |