Water ____ be changed into vapour but it ____ be heated to its boiling point .
| A．may ; can | B．can ; must | C．may ; needn''t | D．must ; may |
The scientist suggested ____ the experiment in a different way.
| A．do | B．to do | C．doing | D．done |
It’s bad for your eyes ____ computer games for a long time.
| A．plays | B．to play | C．play | D．played |
A policeman saw two thieves ____ a girl’s mobile phone on a bus and he caught them at once.
| A．to steal | B．stealing | C．stole | D．stolen |
----Lily, keep the window ____. The sandstorm hasn’t stopped yet. ----OK, I’ll do that.
| A．close | B．closed | C．open | D．opened |
It was great fun _____ a picnic on the hill.
| A．to have | B．of having | C．have | D．had |