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问题 选择题

下列关于惯性的说法，正确的是 (    )

A．只有静止或做匀速直线运动的物体才具有惯性

B．做变速运动的物体没有惯性

C．有的物体没有惯性

D．两个物体质量相等，那么它们的惯性大小相等

答案

答案：D

惯性是物体的固有属性,惯性的大小只与质量有关,一切物体都有惯性.质量越大,惯性越大.

单项选择题

B


Waste can be seen everywhere in the school. Some students ask for more food than they can eat and others often forget to turn off the lights when they leave the classroom. They say they can afford these things. But I don’t agree with them.
Waste can bring a lot of problems. Although China is rich in some resources (资源), we are short of(缺乏) others, for example, fresh water(淡水). It is reported that we will have no coal (煤) or oil to use in 100 years. So if we go on wasting our resources, what can we use in the future and where can we move Think about it. I think we should say no to the students who waste things every day. Everybody should stop wasting as soon as possible.
In our everyday life, we can do many things to prevent waste from happening, for example, turn off the water taps (水龙头) when we finish washing, turn off the lights when we leave the classroom, try not to order more food than we need, and so on. Little by little, everything will he changed. Waste can be stopped one day, if we do our best.

What may happen in 100 years ( )

A．We may still have enough oil.

B．We may still have enough coal.

C．We may have a little oil.

D．We may have no coal or oil to us
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单项选择题

计算机网络系统与分布式系统之间的区别主要是

A．系统物理结构

B．系统高层软件

C．传输介质类型

D．服务器类型
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