单项选择题：阀短路保护目的是使可控硅免受换流变（）短路造成的过电流影响。A.直流侧 B.交流侧

题型：选择题

虎、狼、猫都有犬齿，其功能是 [ ]

A．磨碎食物

B．撕裂食物

C．切断食物

D．咬烂食物

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题型：多选题

一物体作直线运动的v-t图象如图所示，则（　　）

A．前3秒内和前5秒内位移相等

B．物体做加速度不变的匀变速直线运动

C．第2秒末物体的加速度改变方向

D．第4秒末物体的速度改变方向

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题型：阅读理解

阅读理解。

Once there was an old man in a town.He always forgot a lot of things.So his wife always had to say

to him, "Don't forget this!"

One day he went on a long trip alone.Before he left home,his wife said, "Now you have all these things.They are what you need for your trip.Take care of your things during the trip."He went to the station,

bought a ticket and got on the train with it.

About half an hour later,the conductor began to check the tickets.He came to the old man and said,

"Will you please show me your ticket?"The old man looked for his ticket in all his pockets,but he could

not find it.He was very worried. "I can't find my ticket.Ireally bought a ticket before I got on the train."

said the old man.

"I believe you bought a ticket.All right,you don't have to buy another one."said the conductor kindly.

"But how can I know where I'm going? I can't remember my station!"the old man said sadly.

1. The old man in the story was very .

A. kind

B. poor

C. forgetful

D. sad

2. Where is the ticket?

A. The old man forgot to buy it.

B. The old man could not remember where it was.

C. The old man showed it to the conductor.

D. The old man's wife took the ticket away.

3. The old man bought the ticket he got on the train.

A. before

B. after

C. as

D. when

4. The conductor the old man.

A. didn't believe

B. laughed at

C. believed

D. felt soory for

5. The old man was sad because .

A. he sad to buy another ticket

B. he lost all the things his wife gave him

C. he did not know where he was

D. he did not know where he should get off

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题型：单项选择题

口服药治疗甲亢的适应证是（）

A.病情轻、甲状腺较小者

B.胸骨后甲状腺肿

C.结节性高功能腺瘤

D.年龄超过30岁

E.中、重度甲亢

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题型：问答题

物流信息系统必须以异常情况为基础，突出物流动态问题和可能提供的机遇。( )

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阀短路保护目的是使可控硅免受换流变（）短路造成的过电流影响。A.直流侧 B.交流侧

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