Mr. Green is said _____ an experiment to prove the new method of solving the problem when young.
| A．to do | B．to have done |
| C．to be doing | D．to have been doing |
Never before______ so highly successful in his attempts to forecast the weather accurately on
a small scale．
| A．man has been | B．man is |
| C．has man been | D．will be man |
The scientists predict that if present trends______, women in 400 years will be 2cm shorter
and have healthier hearts．
| A．will continue | B．continue |
| C．are continued | D．will be continued |
Bush, before Barack Obama, _______ Brown a similar gift, a leather bomber jacket．
| A．gave | B．have given | C．would give | D．had given |
The students _____ busily when Miss Brown went to get a book she ____ in the office．
| A．had written; left | B．were writing; has left |
| C．had written; had left | D．were writing; had left |
With the world changing fast, we have something new ______with all by ourselves every day．
| A．deal | B．dealt | C．to deal | D．dealing |