Don't forget ________ “Thank you!” when others have helped you．

A．to say

B．to speak

C．to tell

This T-shirt ________ be Kate's．It's too big for her．

A．may

B．must

C．can't

After school, all of the students leave the school, ________．

A．laughing and talking

B．to laugh and to talk

C．laugh and talk

I really don't know________．

A．what's wrong with him

B．what is she writing

C．what does Jim want

He works ________ to make his parents live a better life．

A．hardly

B．hard

C．careful

Tea is ________ popular drink in the world today．

A．the second

B．most

C．the second most

You should take your own bag when ________．

A．shopping

B．shop

C．shops

I ________ the film if I'm free next Sunday．

A．sees

B．saw

C．will see

D．has seen

I can't believe these photos ________ by such a little girl．

A．take

B．took

C．be taken

D．were taken

The air in Beijing is getting much ________ now than a few years ago．

A．clean

B．cleaner

C．cleanest

D．the cleanest