听力每日练习 listen 4584 What on earth is it

 
2--Nanometer is a length scale. It's one billionth of a meter, roughly ten times the size of an individual atom.
 
1--Hmm...it's hard to figure out the exact size,l'm afraid.
 
2--Well,let's make it this way.For comparison ,10 NM is 1000 times smaller than the diameter of a human hair. There are as many nanometers in an inch as there are inches in 400 miles.
 
1--I see.Thank you.
 
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注解：
 
1.on earth到底
2.roughly大致
3.comparison比较
 
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译文：
 
1--麦克，现在好多人都在谈论纳米。它到底是个啥呀？
2--纳米是个长度单位。一纳米等于十亿分之一米，大概比一个原子小10倍吧。
1--嗯…恐怕还不太容易想像得出它的具体大小呢。
2--这样说吧。10纳米比一根头发直径的1/1000还短。一英寸所含的纳米数量等于400米所含的英寸数。
1--这样说我就明白了。谢谢啊。