每日一词：这三种梯子英文分别怎么说？

(1) Ladder 梯子

Prop the ladder against the house in order to get on the roof.把梯子靠在房子上来够到屋顶。

(2) Stepladder 四脚活梯；折梯

The clerk used the step ladder to reach the items on the top shelf.店员用折梯来够顶架上的商品。

(3) Rope ladder 绳梯

There she was. Standing under a tall oak tree.安妮就在那里，正站在一棵高高的橡树下。

"Look," she said. She was pointing at a rope ladder.“看！”她边说边指着一个绳梯。

The longest rope ladder Jack had ever seen.一个杰克从未见过的如此长的绳梯。
                                 - Dinosaurs Before Dark, Magic Tree House 

                                                     —《恐龙谷历险记，神奇树屋》