当加油站周围的空气中悬浮着一定量的汽油蒸气时，遇明火就可能产_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题填空题

当加油站周围的空气中悬浮着一定量的汽油蒸气时，遇明火就可能产生爆炸，说明汽油的着火点较______；汽油主要成分的化学式为C₈H₁₈，完全燃烧时反应的化学方程式为______．加油站常备的消防用品之一是沙子，用沙子灭火的原理是______．

答案

不同物质的着火点是不同的，有的物质着火点高而有的物质着火点低．空气中悬浮着一定量的汽油蒸气时，遇明火就可能产生爆炸，说明汽油的着火点低；

根据题意，反应物是汽油主要成分的C₈H₁₈，生成物是二氧化碳和水，反应条件是点燃，反应的化学方程式为：2C₈H₁₈+25O₂

点燃

.

16CO₂+18H₂O．

灭火的方法有很多种，而用沙子灭火是让沙子覆盖在可燃物上，使可燃物与氧气隔绝，从而达到灭火的目的．

故答案为：低；2C₈H₁₈+25O₂

点燃

.

16CO₂+18H₂O；隔绝氧气．

完形填空

There was a man who had a little boy that he loved very much．Every day after work the man would come home and 36 with the little boy．He would alwa

ys 37 all of his extra time with the little boy.
One night．while the man was at work, he _38 that he had extra work to do for the evening, and that he wouldn’t be able to play with his little boy． 39 he wanted to be able to give the boy something to keep him 40 ．So, looking around his office, he saw a magazine with a large 41 of the world on the cover．He got a(n) 42 ．He removed the map, and then patientely tore it up into small pieces．Then he put all the 43 in his coat pocket.
When he got home, the little boy came __44 to him and was ready to play．The man _45that he had extra work to do and couldn’t play just now．He 46 the little boy into the dinning room, and 47 all the pieces of the map．He spread them on the table．He explained that it was a map of the world, and that by the time he could 48 together, his extra work would be 49 , and they could both play．Surely this would keep the child busy for hours, he thought.
About half an hour later the boy came to the man and said, “Okay, it’s finished．Can we play now?”
The man was 50 , saying, “That’s impossible．Let’s have a look.” And 51 __enough, there was the picture of the world, all put together, every piece in its 52 .
The man said, “That’s amazing! How did you do that?” The boy said, “It’s 53 ．On the 54 of the page is a(n) 55 o

f a man．When I put the man tog

ether the whole world fell into place.”

A．recongnized

A．information

A．looked it up

B．got it around

C．put it back

D．turned it over

D．interesting

判断题

风扇离合器失效后，应立即修复后使用。