当前位置: > 完型:At the same time,a steel pipe(钢管) is p______ down to .A.put B.pulled C.pushed...
题目
完型:At the same time,a steel pipe(钢管) is p______ down to .A.put B.pulled C.pushed
At the same time,a steel pipe(钢管) is p______ down to stop the sides from falling in and to keep out water.
附全文:Nowadays more and more people care about the exploitation(开采) of the natural resources,such as oil.Though there are many kinds of resources,with the fast increase of population and appearance of many more factories,the more we use,the fewer there will be left for the future.Oil is getting less and less year after year.It's said that oil can last for only 50 years.Natural gas perhaps will last about 38 years.
Oil can be used in many ways and it's difficult to imagine what the modern world will be like without oil.But oil isn't easy to find and get out of the earth.Men must study the rocks.When they think the rocks in a certain place may have oil,a metal tower is built.A machine in the tower cuts a hole down into the ground.At the same time,a steel pipe(钢管) is p_______down to stop the sides from falling in and to keep out water.At last if the men are right,usually the oil rushes up the sides with great force(力量) by pressure(压力)of the gas in the top of the rock,and it rushes high into the air.If oil catches a light,there will be a terrible fire.So a kind of cover is fixed on the top of the pipe,and the oil can run out through taps.(活塞)
If we make a well near the middle of the oil field,we can also get gas.Such gas is sent through pipes to towns far away and used in houses and factories like coal gas.
Today oil is under pressure as never before.The price of oil keeps rising all the time.In many countries,the govenments encourage people to save oil as much as possible.

提问时间:2020-08-01

答案
A.put 因为put down有放置的意思,整个句子的意思是 同时,放置一根钢管来防止旁边掉下来的东西和防止水的渗入.
举一反三
已知函数f(x)=x,g(x)=alnx,a∈R.若曲线y=f(x)与曲线y=g(x)相交,且在交点处有相同的切线,求a的值和该切线方程.
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
奥巴马演讲不用看稿子.为什么中国领导演讲要看?
想找英语初三上学期的首字母填空练习……
英语翻译
版权所有 CopyRight © 2012-2019 超级试练试题库 All Rights Reserved.