n.阶梯；横档；(社会、职业、组织等的)阶层

动词ring的过去分词.

Hold the ladder tightly and move up a rung at a time. 抓紧梯子一级一级地往上爬。

Finally, envision yourself climbing the ladder and writing down the pairs of letters that make up each rung. 最后，想像自己正在爬梯子，将构成每对字母的梯级写下来。

He put his foot on the bottom rung to keep the ladder steady. 他用脚踩住最底下的横档稳住梯子。

"Get out!" he exclaimed, lifting his feet to the rung of the chair “滚开！”他大声叫道，提起了双脚，搁在椅子下面的横档上。

He is still on the bottom rung of the political ladder. 他尚处于政治阶梯的最低一级。