____ twice, the postman refused to deliver our letters unless we changed our dog. 
| A．Being bitten | B．Bitten | C．Having bitten | D．To be bitten |
It’s high time that Dalai Lama ______ playing politics.
| A．quit | B．to be quit | C．quited | D．quitting |
It is everybody’s desire that every effort___________ to reduce the pollution in our city.
| A．was made | B．be made | C．will be made | D．would be made |
．—Steve come back because the window is open．
—Yes．but he _______left it open last night．
| A．must have；might have | B．might have；can’t have |
| C．can have；should have | D．might；must have |
_________we sleep together or apart is one of the biggest cultural differences, and only in western societies ______ the feeling that babies should sleep apart from their parents.
| A．No matter; it is | B．Whether; is it |
| C．No matter; there is | D．Whether; is there |
____ they are closest friends is not clear though they live together.
| A．That | B．If | C．What | D．Whether |