问题 选择题

对于反应2SO2(g)+O2(g)⇌2SO3(g),能增大正反应速率的措施是(  )

A.增大容器容积

B.移去部分SO3

C.通入大量O2

D.降低体系温度

答案

A、增大容器容积,减小了体系的压强,压强减小,正反应速率减小,故A错误.

B、移去部分三氧化硫,反应物的浓度不变,生成物的浓度减小,化学平衡向正反应方向移动,所以正反应速率减小,故B错误.

C、通入大量氧气,增大反应物的浓度,能增大正反应速率,故C正确.

D、降低体系的温度,正逆反应速率都减小,故D错误.

故选C.

阅读理解

A dog can’t speak words, but it can “talk”. It has feelings just as you do. At times it may feel angry or afraid. Watch a dog closely. You can see what it is trying to tell you. When you are afraid, you may look down shyly. A fearful dog looks away from you. It may run away too. When you are angry with people, you stare at them and press your lips together. An angry dog also stares. Sometimes the hair along its back stands up.

Do you feel guilty when you have done something you shouldn’t? Dogs can feel guilty, too. At times when I come home, my dog gives me a guilty look. Then I know he’s done something wrong.

Dogs need love and attention. Some dogs are very unhappy when they are left alone for a long time. Some dogs even snap(撕咬) if they don’t get enough attention.

You may have a dog or you may know a dog. Treat it well if you want to have fun with it. Play with it. Take it on walks. Don’t order it round too much. Try not to punish it one time and not the next for doing the same thing. Always remember, a dog has needs and feelings just as you do. Talk to a dog, it’ll talk to you, too.

小题1:If a dog snaps at things, it is because it may ______.

A.feel lonely

B.feel shy

C.be fearful

D.be disappointed小题2:You can tell that a dog has done something bad when _________.

A.its hair stands up

B.it runs away from you

C.it has a guilty expression

D.its lips are pressed together小题3:Which of the following things does the writer advise you to do towards your dog?

A.Never punish the dog

B.Never leave the dog alone

C.Train the dog to take orders from you

D.Train it the way you want to be treated.小题4: Suppose you punish your dog for tearing up a shoe, what should you do the next time it does so?

A.Talk to him

B.Punish it again

C.Pay no attention to it

D.Take it out for a walk小题5:The word “guilty” in the second paragraph most probably means _______.

A.happy

B.excited

C.frightened

D.sorry

单项选择题