下列装置或操作能达到实验目的的是 A.证明CO2密度比空气大 B.量取35mL

题型:选择题

问题:

下列装置或操作能达到实验目的的是

A.证明CO2密度比空气大

B.量取35mL液体

C.测定空气里氧气的含量

D.收集CO2气体

考点:测容器—量筒称量器—天平加热器皿—酒精灯常见仪器和装置的用途
题型:选择题

阅读理解

     People who like travelling have their reasons.They believe that travelling can help them expand their

field of view, especially in the geographical and historical sense.They also think that touring will give them

more chances to enjoy different kinds of food and experience new things  that would never be  brought

by other activities.But those who dislike travelling also have some reasons.

     Travelling, in my opinion, does more good than  harm.Most importantly, it broadens (使扩大) our

mind.We can get in touch with other civilizations (文明), cultures, customs and ideas.

     Through history, most people travelled because of necessity (必要性)-not for pleasure.People

travelled just in order to remain alive.They searched for food to eat or places to live in.They sometimes

ran away from enemies.This is not to say that no one ever travelled just for the fun of it.In ancient times,

for  example, rich Romans travelled all the way to Greece to take part in the Olympic Games, and

festivals.Of course, some people decided to travel just out of curiosity (好奇心). They wanted to find

out what it looked like beyond the horizon  (地平线). Also business travel has been going on for

centuries.Traders could not only make money but also learn to speak several languages and be

introduced to different cultures.

     So, travelling does enrich our mind and draw new ideas to us.There is no doubt that we can get much

from it.

1. The underlined word "expand" in Paragraph 1 can be replaced by "________".

A. widen  

B. protect  

C. lose  

D. decide

2. According to the passage, in the past most people travelled________.

A. for fun  

B. for knowledge

C. to get experiences  

D. to make a living

3. How many reasons for travelling are mentioned in Paragraph 3?

A. Three.  

B. Four.  

C. Five.  

D. Six.

4. In the writer's opinion, travelling can be________.

A. expensive

B. funny      

C. helpful    

D. tiring

5. What's the main idea of this passage?

A. Different kinds of travelling.

B. Travelling enriches our mind.

C. Ways to enjoy yourself while travelling.

D. The advantages and disadvantages of travelling.

题型:选择题

探伤仪中某一通道的场效应管损坏,则该通道停止工作。

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分选性

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乐天公司为一般纳税人,2013年3月3日购入需要安装的机器设备一台,不含税价10万,增值税率17%,另支付运输费1万(未取得税务机关规定的运输费用结算单据),安装费用5000元。3月10日,该设备安装完毕,已达到预定可使用状态。预计该设备的可使用寿命为5年,预计净残值率4%。假设乐天公司没有对该项机器设备计提减值准备。
[要求] 根据上述材料,回答下列各题。

若乐天公司采用双倍余额递减法,则至2017年年底该项设备累计的折旧额为______。

A.99102.4

B.87106.4

C.75431.8

D.78796

题型:选择题

下述关于接地的说法中,那种说法是错的()。

A、接地体可以水平或垂直埋设

B、接地体一般是用50×50×5的角钢在顶部镀锌后打入地下

C、多根接地体并联后,接地电阻不会降低

D、无法确定

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