When people move to another country, they often try _________ the custom of their native land.
| A．to keep on | B．to keep off | C．to keep up | D．to keep down |
After winningwar in Iraq，the country fell intonew worries of economy．
| A．the; the | B．a; the | C．the; ／ | D．a; ／ |
As we know, in our Chinese history _____ was a time when industry was only a home business.
| A．it | B．there | C．that | D．what |
Only when it rains in summer_______ such beautiful rainbows here.
| A．could you see | B．you can see |
| C．you will see | D．can you see |
But as to the fine quality of the products, our price is very _______.
| A．high | B．fit | C．reasonable | D．small |
We should learn how to value what we have ______ it is too late.
| A．when | B．after | C．before | D．until |