[单项选择]Air cannot ______,but it is all around us.


A. is seen
B. see
C. be seen

[单项选择]Human beings cannot exist without air.
A. live
B. breathe
C. exercise
D. grow

[单项选择]According to the passage, we cannot work all the time without（）
A. taking part in sports activities
B. watching sporting events on television
C. listening to sporting events on the radio
D. recreation

[单项选择]Cold air causes the arteries around the heart to constrict.


A. become rigid
B. contract
C. close
D. die

[单项选择]（　） no gravity, there would be no air around the earth.
A. Were there
B. There were
C. Was there
D. There be

[单项选择]Without air resistance, all objects would fall at the same speed ________ their weight.


A. regardless of
B. instead of
C. according
D. despite of

[单项选择]All those who are not the local residents cannot take part in the election campaign.
A. 凡不是当地居民，就能参加选举活动。
B. 凡是当地居民，就能参加选举活动。
C. 选举活动不参加，就不是当地居民。
D. 凡不是当地居民，就不能参加选举活动。

[单项选择]I hope all the precautions against air pollution, ______ suggested by the local government, will be seriously considered here.


A. while
B. since
C. after
D. as

[单项选择]Air pollution refers to the presence of all the following EXCEPT______.


A. harmful solids
B. harmful gases
C. harmful liquids
D. harmful chemicals

[填空题]Stone is all around us, stone is usually very hard, but it can also be s【D1】______Stones have many uses in some countries. A【D2】______carve beautiful things out of soft stones, because they can be shaped easily. In a【D3】______times, people carved small persons or animals out of soft stones which could be carried along with. While in some European c【D4】______, statues are carved from hard stones and they do not change easily. In summer the hot sun s【D5】______on these statues and in winter the snow falls on them, but they still r【D6】______beautiful. Stone is strong and long-lasting. So it is good e【D7】______for buildings. A house built of stone does not catch fire as easily as i【D8】______made of wood. Some stones are colored, so they make the buildings look w【D9】______People can also get a fire with stones. Besides some kinds of stones can be used to m【D10】______jewelry. We’re found stones are really amazing.【D6】