Thank you for all your hard work last week. I don’t think we _____ it without you.
| A．can manage | B．could have managed | C．could manage | D．can have managed |
How many more decades will have to pass ____ scientists succeed in providing a cure for cancer?
| A．when | B．since | C．before | D．until |
--- 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 |
Many clothing manufacturers now substitute artificial silk _____ natural silk to cut down costs of production．
| A．with | B．by | C．for | D．of |
--- Where are you, Nancy?
--- Here in the sitting room, _______ to Professor Smith．
| A．is writing | B．write | C．to write | D．writing |
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 |