Although the causes of cancer_____, we do not yet have any practical way to prevent it.
| A．are being uncovered | B．have been uncovering |
| C．are uncovering | D．have uncovered |
We are living in an age _______ many things are done on computers.
| A．which | B．that | C．whose | D．when |
_______ breaks the law should be punished .
| A．Those who | B．Whomever | C．No mattter who | D．Whoever |
Love is ______ way of life,but not _____ aim of it.
| A．the , the | B．a , the | C．a, an | D．the, an |
--- Must I stay at home, Mum?
--- No, you_____
| A．needn’t | B．mustn’t | C．don’t | D．may not |
--- I’m going to Yulong Snow Mountain tomorrow?
--- ----------
| A．Have a good trip | B．It’s my pleasure |
| C．No way | D．It’s hard to say |