短文填空 Air is very important to everythin

题型:填空题

问题:

短文填空

     Air is very important to everything that lives. But the air we breathe is getting (1)d______. People all

over the world are looking for ways to make it (2)c______ again.

     Have you ever watched the (3)s______ from chimneys (烟囱) rising high in the air? Have you (4)

s______ the smoke from cars and trucks on roads or the smoke from planes? The smoke is not (5)

g______ to breathe. If we want to keep fit and strong, we need to (6)b______ clean air.

     With more and more (7)f______ everywhere and more and more cars, trucks and planes, it is getting more and more (8)d______ to do with the air pollution.

     Scientists have already found (9)w______ to stop or slow down some of the things that make the air

dirty. They will not stop working (10)u______ we have clean air again.

考点:科教类阅读
题型:填空题

化简2(2x﹣1)﹣2(﹣1+x)的结果为 [ ]

A.2x+1

B.2x

C.5x+4

D.3x﹣2

题型:填空题

倾斜井巷中使用的带式输送机,()时,必须装设制动装置。

A.下运时

B.平运时

C.上运时

D.任何时候

题型:填空题

发出的矿灯,最低应能连续正常使用()小时。

A.8

B.11

C.16

题型:填空题

一个单一的集成信息系统的好处之一是()

A.程序和数据之间联系更紧密

B.增加数据冗余

C.降低安全

D.增加数据的可访问性

题型:填空题

不同运输方式之间的相互替代性取决于运输的()

更多题库