月亮为何不掉下来

旁白 neutral

What keeps the moon up in the sky?

是什么把月亮托在天上？

旁白 neutral

Why does not the moon come down?

月亮为什么不掉下来？

旁白 neutral

The moon is a great body

月亮是一个巨大的天体。

旁白 neutral

Its weight is great

它的重量很大。

旁白 neutral

The earth is a great body

地球是一个巨大的天体。

旁白 neutral

Its weight is eighty-one times the weight of the moon

它的重量是月亮重量的八十一倍。

旁白 neutral

Two times three is six

二乘三等于六。

旁白 neutral

The moon and the earth are not very far from one another

月亮和地球彼此相距并不很远。

旁白 neutral

The distance between them is about two hundred and thirty-nine thousand miles

它们之间的距离约为二十三万九千英里。

旁白 neutral

Because they are great bodies and near one another, the attraction between the moon and the earth is very great

因为它们是巨大的天体又彼此靠近，月亮和地球之间的引力非常大。

旁白 neutral

Why does the moon not come down to the earth?

月亮为什么不落向地球呢？

旁白 neutral

That is a question

这是一个问题。

旁白 neutral

The answer is: " Because it is going round the earth."

答案是：“因为它在绕着地球转。”

旁白 neutral

The moon goes round the earth

月亮绕着地球转。

旁白 neutral

This is a cord in my hand

这是我手里的一根绳。

旁白 neutral

The cord has a weight at its end

绳的末端系着一个重物。

旁白 neutral

The weight is hanging down on the cord which is in my hand

重物顺着我手里的绳垂了下来。

旁白 neutral

I make the weight go round on the cord

我让重物在绳上绕圈飞旋。

旁白 neutral

I keep the end of the cord in my hand

我把绳的一端一直握在手里。

旁白 neutral

Now I let the end of the cord in my hand go

现在我把手里绳的一端松开。

旁白 neutral

The weight goes off in a straight line

重物沿直线飞了出去。

旁白 neutral

It takes the cord with it

它把绳也一起带走了。

旁白 neutral

The pull of the cord in my hand kept the weight from going off in a straight line

我手里绳的拉力使重物没有沿直线飞出去。

旁白 neutral

The attraction between the earth and the moon keeps the moon from going off in a straight line

地球和月亮之间的引力使月亮没有沿直线飞出去。

旁白 neutral

The moon goes round and round the earth, month after month

月亮一圈又一圈地绕着地球转，月复一月。

旁白 neutral

It does not get farther from the earth

它不会离地球更远，

旁白 neutral

or nearer to the earth

也不会离地球更近。

旁白 neutral

It keeps about the same distance from the earth

它与地球始终保持大致相同的距离。