—What about going swimming this afternoon?
—You ______ be joking! Don't you know I'm afraid of water?
A. may B. can C. must
--What would you do if you ____ a million dollars?
--I’d give it to the charity
| A．win | B．won | C．will win | D．is to win |
Can you call me when you ________ home?
| A．get back to | B．get to back | C．get back | D．get to |
We are from China and we _______ Chinese.
| A．say | B．talk | C．speak | D．tell |
Some students are so ______ that they often make mistakes in their homework.
| A．carful | B．serious | C．careless | D．successful |
__ we are young, we can still do something to help protect the environment.
| A．If | B．Since | C．Because | D．Though |