Though our pilots today will try to approximate the original landing site,they’re___the winds,so who knows where they’ll drift off to
| A．at the mercy of |
| B．at the call of |
| C．at the service of |
| D．at the expense of |
Canada is a country ______ many different nationalities as well as one with foreign immigrants ______ the majority of its population．
| A．consisting of; making up | B．making up of; occupied with |
| C．made up of; consisting of | D．consisted of; taking up |
．--- Where are you, Nancy?
--- Here in the sitting room, _______ to Professor Smith．
| A．is writing | B．write | C．to write | D．writing |
--- Where will you start your work after graduation?
--- Mmm, it’s not been decided yet．I _______ continue my study for a higher degree．
| A．can | B．must | C．would | D．might |
How many more decades will have to pass ____ scientists succeed in providing a cure for cancer?
| A．when | B．since | C．before | D．until |
_______ information cost him many chances of finding jobs．
| A．Lack of | B．Short of | C．Lack | D．Lacking of |