________ global temperatures rising, the UN Climate Change Conference was held in Cancun（坎昆）, Mexico last year．
A．Prevented B．Preventing
C．Having prevented D．To prevent
The young couple are trying to save as much as possible ________ they can afford a flat by the end of next year．
A．so that B．even though C．in case D．as if
When I got to the checkout counter, I realized I didn’t have enough money, so I kept ________ I really needed and left the rest．
A．what B．which C．that D．this
Although it was not named ________ 1782, this kind of metal was used as early as 5300 BC．
A．in B．for C．until D．since
--Who is late for class again?
--________ you ask? Tim, of course．
A．Can B．Would C．Could D．Need
--Shall I give you a ride to the Capital Airport?
--Thank you．________．
A．If you like B．It couldn’t be better
C．Of course, you can D．It’s up to you
