及物动词
1. This shoe is rubbing. 这只鞋子磨痛脚后跟。
2. rub是什么意思
2. She rubbed her shoes with a cloth to make them shine. 她用一块布把鞋擦亮。
不及物动词
1. The door rubs on the floor. 这门擦到地板了。
名词
1. There's the rub. 问题难就难在这里。