Though English is hard ________, you should still do everything you ________ it well.

[　　]

A．to be learned; can study

B．to be learned; can to study

C．to learn; can study

D．to learn; can to study

Have you given up ________ whisky before breakfast?

[　　]

Please ask the children to put things ________ they can easily get them.

[　　]

In fact ________ is a hard job for the police to keep order in an important football match.

[　　]

－Smoking is bad for your health.

－Yes, I know. But I simply can't ________.

[　　]

The fire spread through the hotel very quickly but everyone ________ get out.

[　　]

The famous scientist grew up ________ he was born and in 1930 he came to Shanghai.

[　　]

You should make it a rule to leave things ________ you can find them again.

[　　]

－________ the sports meet might be put off.

－Yes, it all depends on the weather.

[　　]

All the preparations for the task ________, and we are ready to start.

[　　]

A．completed

B．complete

C．had been completed

D．have been completed