问题 选择题

下图是氢氧燃料电池构造示意图。关于该电池说法中错误的是

A.a极是负极

B.正极的电极反应是:O2+2H2O+4e- = 4OH-

C.电子由a通过灯泡流向b

D.通入的气体Y为O2

答案

答案:B

题目分析:A项:从图中可以看到,H+移向b极,可知b极为负极,a极为正极,故错。C项:电子是由b通过灯泡流向a的,故错。D项:b极为负极,通入的是H2,故错。故选B。

点评:本题考查的是燃料电池的知识,解答本题先从H+的移向入手,在原电池中阳离子移向负极,即可作答本题。

单项选择题
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     You might have such problems with a friend as follows:

     New friends replace an old friendship. You used to walk home from school with your friend, and

share everything. Now your friend is with someone else all the time and is always "too busy" for you.

One of your friends reveals a secret. You can not believe your ears. The deep, dark secret you shared

with your best friend was repeated back to you by someone you hardly know. Your friend told! Why

has your friend turned against you?

     These things hurt you. They make you feel angry and sad. In each situation your friendship would feel

threatened. When you are upset with someone, it is a good idea to go off by yourself and sort out your

feelings. Go for a walk, talk to yourself, and look at what you feel. Allow your anger to explode where

no one is around to hear you. Then calm down. Think through what you want to say to your friend.

     It helps to stand back and take a fresh look at your friendship. Just because you have been very close

to someone but it does not mean you are linked together or that you own one another. There should be

room in your friendship for other friends, higher achievements, slips of the tongue, sometimes a conflict is

a sign that you need to change the kind of friendship you have.

     It also helps to put yourself in your friend's shoes. What would you do if you found that you had more

fun with a new friend? What if you told your friend's secret to someone when you did not mean to? It is

painful to be the other, too.

1. What is the passage mainly about?

A. How to make friends with others.

B. How to solve some problems you may have with your friends.

C. How to get along with your friends.

D. How to avoid being hurt by your friends.

2. The underlined word "reveals" in paragraph 3 probably means "______".

A. treasures

B. records

C. forgets

D. lets out

3. When you find your friends turn against you, you'd better ______.

A. find a suitable place to explode your anger and then think carefully

B. quarrel with them at once

C. write a letter saying you don't want to be their friend again

D. find new friends, too

4. The author seems to believe that ______.

A. new friends can't replace old friends

B. a secret between two friends should be told to a third person

C. thinking more in your friend's position can solve some problems

D. ignore those friends who turn against you