In 2000, Chinese scientists completed their part of the international human genome project, ______ that Chinese scientists are among the world’s best.
| A．to prove | B．proving | C．proved | D．having proved |
Every possible means _______to prevent the air pollution, but the sky is still not clear.
| A．is used | B．are used | C．has been used | D．have been used |
The doctor had almost lost hope at one point, but the patient finally______.
| A．pulled out | B．pulled through | C．pulled up | D．pulled over |
All the neighbors admire this family_______ the parents are treating their child like a friend.
| A．why | B．where | C．which | D．that |
—Were you all frightened at the sound of the fire alarm?
— No. Everyone stayed _______ and obeyed the police.
| A．quiet | B．calm | C．silent | D．peaceful |
—_______when has the country been open to international trade?
— 1978,I suppose.
| A．Since | B．In | C．From | D．After |