Take a strip of paper.
拿一条长长的纸条。
Twist it once, then glue the two ends.
把它拧一下，再把头尾粘起来。
You get a ring with only one side.
你就得到一个只有一面的环。
A small bug can walk on it without crossing an edge.
小虫爬上去，不用翻边就能走完全程。
This is called a Mobius strip.
它的名字，叫莫比乌斯带。
It looks simple, but it is very strange.
看着简单，其实奇怪得很。
Some roads use this crazy idea.
有的公路设计，就借用了它的点子。
