引力与重量

旁白 neutral

Here are two bodies

这里有两个物体。

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One is a great body. It is the earth

一个是大物体，它是地球。

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The other is a small body. It is an apple

另一个是小物体，它是苹果。

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The apple is coming down to the earth. Why?

苹果正落向地球。为什么？

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It is coming down because there is an attraction between the two bodies

它落下来，是因为两个物体之间有引力。

旁白 neutral

The attraction between them makes the apple come down

它们之间的引力使苹果落下来。

旁白 neutral

All bodies which have weight have an attraction for one another

所有有重量的物体，彼此之间都有引力。

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Here are two bodies. These are springs

这里有两个物体，它们是弹簧秤。

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Which body has the greater weight?

哪个物体的重量更大？

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Here are two men

这里有两个人。

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This man is thin. His body is thin

这个人是瘦的，他的身体很瘦。

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This man is fat. His body is fat

这个人是胖的，他的身体很胖。

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Which man's weight is greater?

哪个人的重量更大？

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This is a scale

这是一台秤。

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A scale is an instrument for measuring weight

秤是测量重量的仪器。

旁白 neutral

Which man's weight is greater? They are on the scale

哪个人的重量更大？他们在秤上。

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The weight of the thin man is one hundred pounds

瘦的人重一百磅。

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The weight of the fat man is two hundred pounds

胖的人重两百磅。

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Clocks are instruments for measuring time

钟是测量时间的仪器。

旁白 neutral

This is a watch

这是一块手表。

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Watches and clocks are instruments for measuring time

手表和钟都是测量时间的仪器。

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This is an instrument for measuring heat

这是测量热量的仪器。

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A yard measure is an instrument for measuring distance

码尺是测量距离的仪器。

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Inches, feet, yards, metres, and miles are measures of distance

英寸、英尺、码、米和英里都是距离的单位。

旁白 neutral

All bodies have an attraction for one another

所有物体彼此之间都有引力。

旁白 neutral

If the bodies are great, the attraction between them is great

如果物体大，它们之间的引力就大。

旁白 neutral

If the bodies are small, the attraction is small

如果物体小，引力就小。

旁白 neutral

If the bodies go farther from one another, the attraction gets smaller

如果物体离得越远，引力就越小。

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Here is a light. Here is a square

这里有一盏灯，这里有一个方块。

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It sends out light in every direction

它向四面八方发出光。

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I put the square at different distances from the light

我把方块放在离灯不同的距离处。

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At distance one, it gets all the light which is going out between the lines

在距离一处，它得到两线之间发出的全部光。

旁白 neutral

At distance two, it gets one fourth of the light

在距离二处，它只得到四分之一的光。

旁白 neutral

At distance three, it gets one ninth of the light

在距离三处，它只得到九分之一的光。

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It is the same with the attraction between bodies

物体之间的引力也是同样的道理。