wear down
1. 磨损，磨薄，磨短：
The point of the pencil had been worn down when I finished this letter.
写完这封信时铅笔已经磨得很短了。
2. 使衰弱，使筋疲力尽；使厌倦：
Looking after a high-spirited child can soon wear a person down.
照看一个精力旺盛的孩子，一会儿就能把人搞得筋疲力尽。
3. 由于坚持而克服…的反对，逐渐克服；说服：
Their persuasion has worn down her opposition.
他们已经说服她不再反对。
4. 削弱，消耗：
to wear down the enemy forces
消耗敌军
祝你学习进步，更上一层楼！(*^__^*)
有不会的可以再问我:）
