1 . ―Do you know where David is? I couldn’t find him anywhere.
―Well. He ______ have gone far — his coat’s still here.

A．needn’t	B．can’t
C．mustn’t	D．wouldn’t

2 . Being constantly exposed to advertisements is annoying, but it ______ be pleasant sometimes.

A．shall

B．need

C．can

D．must

3 . The World Wide Web is sometimes jokingly called the World Wide Wait because it ______be very slow.

A．should

B．must

C．will

D．can

4 . How_________I help them to understand when they won’t listen to me?

A．can

B．would

C．may

D．must