威尼斯，为什么建在水上？

Venice is a city built on water. 威尼斯是一座建在水上的城。 Long ago, people drove wooden piles into the lagoon. 很久以前，人们把木桩打进潟湖。 They built houses on top of the piles. 他们在木桩上面盖房子。 The streets are actually canals. 这里的街道其实就是水道。 People move around by boats. 人们出门靠坐船。 That is how a whole city floats on water. 一整座城就这样漂在水上。