【英语时差8,16】糖罐子里的秘密（上）

If you’ve ever had to dig a hole and then fill it back in, you may have noticed a mysterious thing: there was always a little dirt left over. This can often be seen when construction crews dig down to get at sewer¹ pipes or electric cables. But how can there be more dirt going in than there was coming out? The answer is that the amount of soil itself remains² the same; what has changed is the arrangement of the individual grains. To see how this happens, think of a sugar bowl. If every crystal of sugar is evenly spaced, the ratio of crystals to empty space will be 60 – 40. That’s true no matter how big the bowl: 40% of the inside will always be empty.

1 sewer   

n.排水沟，下水道

参考例句：

• They are tearing up the street to repair a sewer. 他们正挖开马路修下水道。
• The boy kicked a stone into the sewer. 那个男孩把一石子踢进了下水道。

2 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。