Every one of us must know this: _________ we live can we save the earth．
| A．by changing the way only | B．by only changing the way |
| C．only by changing the way | D．by changing only the way |
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In the years____, the city government will take effective measures to bring the price of the house under control.
| A．following | B．followed | C．follow | D．to follow |
.
According to some doctors, one of the ways to prevent us from growing old is to make sure
that our brains get enough___.
| A．performance | B．exercise | C．experience | D．sport |
.
We are ____faced with the necessity to recognize that having more people implies a lower standard of living.
| A．readily | B．smoothly | C．unavoidably | D．deliberately |
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Although many people view conflict as bad, conflict is sometimes useful _______ it forces people to test the relative merits of their attitudes and behaviors.
| A．by which | B．to which | C．in that | D．so that |
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— I phoned you at 7 yesterday evening but nobody answered.
— Oh, I ________ my dog in the park then.
| A．walked | B．was walking | C．had walked | D．would walk |