Each member country WTO must ___________ its laws and regulations and compete on the principle of fairness and cooperation.
| A．submit to | B．cater to | C．correspond to | D． relate to |
_____ you have worked out the first problem, you may go on to work on the second.
| A．Even if | B．Unless | C．Now that | D．Though |
Most of the evidence was destroyed in the fire. _____, it would be almost impossible to prove Jim guilty.
| A．Anyhow | B．However | C．Besides | D．Thus |
_____ life exists on any other planet in the solar system still remains a question.
| A．Why | B．Whether | C．How | D．Where |
It was almost midnight when a fire _____ in the neighborhood.
| A．blocked out | B．turned out | C．broke out | D．died out |
There is a peaceful and calm _____ in the country, quite different from that of a big city.
| A．climate | B．atmosphere | C．system | D．situation |