Unit 12 A “A Fly”

Passage A
A Fly
A fly can walk up a wall. It can walk upside down, too. But how does the fly do that?
A fly has six legs. It walks with three legs up and three legs down. Each leg has a little sticky pad. The sticky pad almost likes a shoe. The pads stick to the wall. So a fly can walk up a wall and it doesn't fall.
苍蝇
苍蝇能够在墙上行走。它也可以头朝下走。但是苍蝇是怎么做到这些的呢？苍蝇有六条腿。它走的时候，三条腿朝上，三条腿朝下。每条腿上都有一个小小的粘性的趾。这种粘性的趾像鞋一样。这些趾可以粘附在墙上。所以苍蝇能够在墙上行走而不掉下来。