Mr. Smith works as a government official now, but he ______ in a middle school for 5 years.
| A．has worked | B．worked | C．had worked | D．had been working |
.Many parents think it will be of great use for their children to ______ from home and earn their own living.
| A．run away | B．take away | C．keep away | D．get away |
Color - blind people often find it difficult to ______ between red and green.
| A．distinguish | B．compare | C．contrast | D．distribute |
Those two countries are similar ______ they both have heavy snowfalls during the winter.
| A．to which | B．in that | C．so that | D．except that |
It ______ long befor the Chinese Space Center ______ Shenzhou VII Spacecraft,becoming the third country to send an astronaut to "walk" in space after the United States and the former Soviet Union (now Russia).
| A．will not be,launches | B．was not,launched | C．will be,launches | D．was not,had launched |
China successfully held the 29th Olympic Games,fulfilling the promise Beijing ______ in its Olympic bid.
| A．making | B．to make | C．makes | D．made |