_______, there would be no air around the earth.
| A.There were no gravity | B.There was not any gravity |
| C.Were there no gravity | D.was there no gravity |
Some students often listen to music _____ classes to refresh themselves.
| A.between | B.among | C.over | D.during |
.—____ when has the country been open to international trade?
—1978, I suppose.
| A.Since | B.In | C.From | D.After |
I think he is taking an active part in social work. I agree with you ______ .
| A.in a way | B.on the way | C.by the way | D.in the way |
Experts have been warning _____ of the health risks caused by passive smoking.
| A.at a time | B.at one time | C.for some time | D.for the time |
He was told that it would be at least three months ___ he could recover and return to work.
| A.when | B.before | C.since | D.that |