1. 楼梯
Stairs are a set of steps inside a building which go from one floor to another.
e.g. Nancy began to climb the stairs...
南希开始爬楼梯。
e.g. We walked up a flight of stairs...
我们上了一段楼梯。
2. 一层楼梯;一段楼梯
A stair is a flight of stairs.
e.g. I followed her down the stair.
我跟着她下了楼梯。
3. 一级楼梯
A stair is one of the steps in a flight of stairs.
e.g. Terry was sitting on the bottom stair.
特里正坐在最下面的一级楼梯上。
名词楼梯;梯级网络阶梯;一级;台阶