问题 选择题

研究人员研制出一种锂水电池,可作为鱼雷和潜艇的储备电源。该电池以金属锂和钢板为电极材料,以LiOH为电解质,使用时加入水即可放电。关于该电池的下列说法不正确的是(  )

A.水既是氧化剂又是溶剂

B.放电时正极上有氢气生成

C.放电时OH向正极移动

D.总反应为:2 Li+2H2O=2 LiOH+H2

答案

答案:C

由于Li属于碱金属,化学性质活泼,金属性大于铁,所以,该电池的总电极反应由题意可知:2Li+2H2O=2LiOH+H2↑,负极:Li,正极:钢板。负极反应为:Li-e=Li,放电时,OH向负极移动,故C选项不正确。

完形填空

阅读短文,根据要求完成下面各小题。

In a classroom in any countries , the teachers teaches more than art or history or language. He or she teaches something behind---the culture of the country.

In a country such as the United States, people with different history, culture and language join together and the pay much attention to personal ideas. Teachers try to make each student special. Students do not have to remember a lot of information , instead, they work and find answers by themselves. There is often discussion in the classroom..

At an early age students learn to have their own ideas. Their education encourages personal thought.

The importance is placed on how to arrive at an answer and not only to get the correct answer.  

In most Asian countries , people have the same language , history and culture. Perhaps for this reason , the education there pays more attention to group goals than person ideas. Children in China and Japan often work together and help each other on homework. In the classroom, the ways of teaching are often very traditional. The teachers says , and the students listen. There is not much discussion. Instead , the students repeat rules or information that they have been taught in order to keep them in mind .

In many ways these differences come from different educational ideas. In western countries teachers are taught to help students to learn. They make it easier for the students to learn by themselves. In some Asian countries , however , teachers often feel that their job is to pass knowledge to students.

A: 根据短文内容简要回答问题。

小题1: What does the education in the United States encourage ?

________________________________________________

小题2: Which does the education in some Asian countries pay more attention to, group goals or personal ideas?

__________________________________________________

B: 将短文中画线的句子译成汉语。

小题3:___________________________________________________________________

小题4: ________________________________________________________________

小题5: 请给短文拟一个恰当的标题。

___________________________________________________

问答题 简答题