We must try our best ________ pollution ________ again and again.

A. to stop; happen

B. to stop; from happening

C. stopping; happening

D. stopping; to happen

?It's too hot. Would you mind ________ the door?

?________. Please do it now.

A. to open; OK

B. opening; Certainly not

C. opening; Of course

D. to open; Good idea

________ is really hard ________them to climb Mount Qomolangma.

A. This; to

B. It; for

C. This; for

D. It; to

?What shall we do this weekend?

?Why ________ to the Qinglongshan Park?

A. don't go

B. not to go

C. not you go

D. not go

They preferred ________ in bed rather than ________ horses.

A. to lie, to ride

B. lying, riding

C. to lie, ride

D. lying, ride

I can't send an e-mail. Would you please show me ________ it?

A. doing

B. to do

C. what to do

D. how to do

When they went into the park, they saw someone ________ Chinese Kungfu.

A. plays

B. played

C. to play

D. playing

Aunt Li often asks her son ________ too much meat. It's bad for his health.

A. don't eat

B. not to eat

C. not eat

D. to not eat

Father is sleeping. You'd better ________ quiet.

A. to keep

B. keep

C. keeping

D. kept

Some boys of Class One enjoy ________ music.

A. listen to

B. listens to

C. listening to

D. listened to