问题 选择题
下列说法正确的是(  )

A.苯丙烯的同分异构体(包括顺反异构)共有5种

B.甲苯能使酸性高锰酸钾溶液褪色,而甲基环己烷不能,说明有机物分子中的基团间存在相互影响

C.芥子醇

能发生氧化、取代、水解、加聚反应

D.将少量某物质的溶液滴加到新制的银氨溶液中,水浴加热后有银镜生成,该物质不一定属于醛类.

答案

答案:D

阅读理解

阅读理解。

      No air means death. Though we can't see it, there is air all around us, so air is everywhere and gives life to

every living thing.

      Without it we can't live. Bad air makes people ill. We must have fresh air to keep us in good health.

      In the city there are many people and there are too many cars running on the roads the gas which the cars

spread (传播) out is full of poison (有毒). Every day we breathe it in again and again. This makes us feel sick.

      Besides the cars, there are many factories too. From the chimneys (烟囱) of these factories, we usually get

black and grey smoke. This kind of smoke, when mixed with air, is dangerous to our health because it contains

much poisonous gas. So in order to keep ourselves healthy we should go out to the countryside to breathe more

fresh air.

1. Air is very important because _______. [ ]

A. We can't see it.

B. It is everywhere.

C. It gives life to every living thing.

D. It does no harm to people's health.

2. We must have fresh air to _______. [ ]

A. make our room healthy

B. keep us healthy

C. keep out house clean

D. see every thing clearly

3. The gas which the cars spread out is _______ the black smoke that comes out of the factories. [ ]

A. as grey as

B. as much as

C. as dense as

D. as little as

4. In the city, the air is not so clean as that _______. [ ]

A. in factories

B. out of doors

C. in the countryside

D. indoors

5. We can't get more fresh air when we are in _______. [ ]

A. hills

B. countryside

C. seaside

D. big cities

单项选择题