荷叶上两滴水珠接触时,能自动结合成一滴较大的水珠,这一事实说明分子间存在着___

题型:填空题

问题:

荷叶上两滴水珠接触时,能自动结合成一滴较大的水珠,这一事实说明分子间存在着______。封闭在注射器筒内的空气很容易被压缩,这实验说明分子间有______。个大粒圆的爆米花芳香扑鼻,该现象说明分子不停地____________。

考点:分子的热运动
题型:填空题

为保护人身和二次设备的安全,要求电流互感器在运行中()。

A.二次侧严禁开路;

B.必须一点接地;

C.严禁超过规定容量加带负荷

题型:填空题

— The drunk driver wishes he _____ so many injuries in the accident.

— But he _____. [ ]

A. hadn't caused; had  

B. didn't cause; did

C. hadn't caused; did  

D. hasn't caused; has

题型:填空题

阅读理解。

     You either have it, or you don't- a sense of direction, that is. But why is it that some people could find their

way across the Sahara without a map, while others can lose themselves in the next street?

     Scientists say we're all born with a sense of direction, but it is not properly understood how it works. One

theory is that people with a good sense of direction have simply worked harder at developing it. Research being

carried out at Liverpool University supports this idea and suggests that if we don't use it, we lose it.

     "Children as young as seven have the ability to find their way around. Says Jim Martland, Research Director of the project." However, if they are not allowed out alone or are taken everywhere by car, they never develop

the skills."

     Jim Martland also emphasizes that young people should be taught certain skills to improve their sense of

direction. He makes the following suggestions:

     If you are using a map, turn it so it relates to the way you are facing.

     If you leave your bike in a strange place, put it near something like a big stone or a tree. Note landmarks on

the route as you go away from your bike. When you return, go back along the same route.

     Simplify the way of finding your direction by using lines such as streets in a town. Streams, or walls in the

countryside to guide you. Count your steps so that you know how far you have gone and note any landmarks

such as tower blocks or hills which can help to find out where you are. Now you need never get lost again!

1. Scientists believe that ______.

A. some babies are born with a sense of direction

B. people learn a sense of direction as they grow older

C. people never lose their sense of direction

D. everybody possesses a sense of direction from birth

2. What is true of seven-year-old children according to the passage?

A. They never have a sense of direction without maps.

B. They should never be allowed out alone if they lack a sense of direction.

C. They have a sense of direction and can find their way around.

D. They can develop a good sense or direction if they are driven around in a car.

3. If you leave your bike in a strange place, you should ______.

A. tie it to a tree so as to present it from being stolen.

B. draw a map of the route to help remember where it is.

C. avoid taking the same route when you come back to it.

D. remember something easily recognized on the route.

4. According to the passage, the best way to find your way around is to ______.

A. ask policemen for directions.

B. use walls, streams and streets to guide yourself.

C. remember your route by looking out for steps and stairs.

D. count the number of landmarks that you see.

题型:填空题

离心压缩机的特点有哪些?

题型:填空题

当炉体有耐火砖砌体时需要烘炉,烘炉时间一般小型锅炉为3~7d,砌筑砂浆含水率应降到20%以下。( )

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