题干

下列关于能源的说法正确的是(   )

A:煤、石油是当今人类利用的主要能源,它们是可再生能源

B:天然气是一种清洁的能源,人类可以无尽地开发利用

C:核电站发电的能量转化过程是:核能→内能→机械能→电能

D:热传递改变物体的内能是不同形式的能的相互转化

上一题 下一题 0.0难度 选择题 更新时间:2010-10-14 08:03:40

答案(点此获取答案解析)

C

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    If you remember the following six ways of information, you'll know how to protect yourself. You'll be much safer at school and in your everyday life.

1)Always notice the environment around you. You shouldn't walk alone out. Make sure where the public phones are. If anything dangerous happens, you can find them quickly.

    Don't use earphones when running in the schoolyard or on the street. You will keep yourself from the outside world and can easily get into trouble.

    When taking a bus, school bags should be carried towards the front of your bodies instead of putting them on your backs. When buses are crowded, it is easy enough for thieves to steal the things in the bag on your back.

    If you are followed by a stranger, cross the street and go in the other direction. Let the stranger know he or she is there. Next, go and get help from others if it is necessary. Don't go home directly. You are safer in the street than you are in your home or in a lift.

    If you have to take a bus to a place far away, try to get to the stop only a few minutes before the buses leave. On buses, don't sit alone. You should sit behind the driver or with friends. Don't sleep.

    Don't play with matches or candles, because it may cause fire. If your house catches fire and you have to escape through smoke, move on your hands and knees with your head 30-60 centimeters above the floor. Please remember there is cleaner and cooler air near the floor during the fire.

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