化学课上,老师做了一个小实验:取一个烧杯,杯底放一支短蜡烛,并放入一些碳酸钙粉末

题型:填空题

问题:

化学课上,老师做了一个小实验:取一个烧杯,杯底放一支短蜡烛,并放入一些碳酸钙粉末.把蜡烛点燃,沿烧杯壁倒入一些盐酸,观察到碳酸钙______,同时有______产生,然后蜡烛熄灭,蜡烛熄灭的原因是______.

考点:灭火的原理和方法
题型:填空题

Aunt Polly had told Tom to paint the whole fence (栅栏)in front of the house. He thought of the other boys out for the day enjoying themselves and he felt very unhappy. Then he had an idea! He picked up the brush and started painting slowly and carefully. Soon, his friend Ben Rogers appeared, eating an apple. Tom pretended (假装) not to see him.

“Tom!” Ben said. “Why are you working?”

“Oh, it’s you, Ben,”Tom said, “I didn’t notice you.”

“I’m gong for a swim,” Ben said, “but you don’t’ want to come. You want to work, don’t you? It’s much nicer!” Ben laughed loudly. Tom looked seriously at Ben and said. “What is work? What do you call work?”

“Isn’t that work?” Ben asked.

“Well, no. Does a boy get the opportunity to paint a fence every day? You’ve never painted a fence, have you? Auntie says I have to do it with great care!’

“Pleas, Tom. Let me do a little,” said Ben.

“No, Ben. If you do, you’ll do it wrong. You can’t paint very well. If it was the back fence wouldn’t mind, but it isn’t.”

“I won’t do it wrong. I’ll be really careful. I’ll give you my apple.” Tom gave him the brush and paint with a sad face, but in his heart he was glad, His trick had worked.

After Ben got tired and left, other boys came along and Tom said the same things to them. Soon, the whole fence was painted white, but not by Tom. He felt very clever because he had discovered something important about the way people are. People only want what they can’t have or want to do what they shouldn’t do.

小题1:Which of the following has the closest meaning to the underlined word “opportunity” on this passage?

A.Reward

B.Interest.

C.Abilityy.

D.Chance.小题2:Why did Tom pretend not to see Ben?

A.Because he wanted Ben to believe that the was enjoying the work.

B.Because he would like to try his best to attract Ben’s attention.

C.Because he did not want Ben to see the fact that he had to work.

D.Because he was afraid that Ben might laugh at him if the saw him.小题3:What can we infer (推断) from the story?

A.Aunt Polly gave Tom a lot of pocket money for what he had done.

B.Ben and the other boys might feel unhappy when they found out the troth.

C.Tom believed that he had discovered how to deal with different people.

D.Everyone thought Tom clever when they realized what had happened.

题型:填空题

首选骶髂关节正位摄影的疾病是()

A.脊柱裂

B.脊柱结核

C.脊柱侧弯

D.脊柱转移瘤

E.强直性脊柱炎

题型:填空题

锅炉干法保养时,锅筒内放置干燥剂10天后检查失效情况,以后每隔()检查或更换1次干燥剂。

A、半个月

B、1个月~2个月

C、2个月~3个月

D、3个月~4个月

题型:填空题

指令流水线将一条指令的执行过程分为四步,其中第1、2和4步的经过时间为△t,如下图所示。若该流水线顺序执行50条指令共用153△t,并且不考虑相关问题,则该流水线的瓶颈第3步的时间为()△t。

A.2

B.3

C.4

D.5

题型:填空题

下列()属于社区的特征。

A.有统一的行动

B.具有许多共同的服务

C.有相同的生活方式和文化

D.有多种共同需要

E.具有多方面的共同利益

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