21、A: How often do you surf the Internet?

B:_________ ．

A．Twice a week．            B．Two weeks a time           C．A week twice．

20、A lot of vegetables help us to keep in good __________．

A．habit          B．body            C．health

19、A: What's the matter?

B:_________ ．

A．I have a sore back．                B．I have a water melon．          C．I have many friends．

18、A: I have a _______．

B: You shouldn't eat anything．

A．headache           B．fever           C．stomachache

17、A: What are you doing __________ vacation?

B: We are camping．

A．for          B．with           C．a(chǎn)bout

16、A: __________ are you staying in the countryside?

B: For about two weeks．

A．How much         B．How long          C．How often

15、They finished ________ the classroom two hours ago．

A．to clean         B．clean          C．cleaning

14、A: ___________ do you get to school?

B: I take the subway．

A．What           B．How           C．Why

13、A: ____________ is it from your home to school?

B: More than 5 miles．

A．How far           B．How long           C．How many

12、A: How does your father go to work?

B: _________．

A．By the bus．                B．To the bus．             C．By bus