问题 选择题

下图是日常生活中常见电动自行车主要部件之铅蓄电池结构示意图,有关说法不正确的是

A.铅蓄电池属于二次电池

B.实际使用过程中可以无限次充放电

C.使用过程中负极发生氧化反应

D.铅蓄电池体积大有污染还不是最理想的电池

答案

答案:B

铅蓄电池可重复充放电,属于二次电池,也就是充电电池;放电时,做为原电池,负极发生氧化反应;由于可能造成重金属铅的污染,所以不是最理想的电池;

随着充电次数的增多,电池的容量减小、电池的内阻增大,电池的性能越来越差,故选项B符合题意

阅读理解

阅读理解

       Most people have jobs. They go to work nearly every day.  Some people are lucky. Either they

have very interesting jobs or they make a lot of money.  Most people are not  so lucky.  Either their

jobs are not very interesting or they don't make much money.  The most interesting jobs are often the

most difficult. People take a long time to learn how to do them.  Doctors study for at least six years

after finishing school.

       Some young people have interesting and high-pay jobs.  Many young players do their work

successfully.  Football and tennis stars are usually under 35 years old.  Older'peopje usually cannot

play these sports very well. They cannot move fast enough. Golf, however, is a good sport for older

people.  Many golf players are quite old, but they can play it successfully.

       Most people work until they are 60 0r 65 years old.  Then they retire and have a lot of free time.

Some people never retire though. These people usually have very interesting jobs. Writers, artists,

scientists and actors usually work until they die. Their work is their life.

根据短文内容,完成下列句子,每空一词 。  

1. Some_______ people have interesting or high-pay jobs,_______most people don't have such

good luck.

2. Some jobs_______a long time to learn because they are________ .

3. Young players can________ very fast, so many of them play these ________ like football

and tennis very _________ .

4. Golf is a good sport for_______ people.

5. Most people keep ________ until the age of 60 or 65.  But writers, artists, scientistsand actors

can work all their                   .

判断题