点击下方单词,选择对的这个单词
点击下面链接下载与本句相关的学习资源，包括PDF教材和音频练习，方便课后复习：
1. 没完没了的；无休止的；毫无起色的If you describe a bad situation as grinding, you mean it never gets better, changes, or ends.
1. a harsh and strident sound (as of the grinding of gears)
2. material resulting from the process of grinding
e.g. vegetable grindings clogged the drain
3. the wearing down of rock particles by friction due to water or wind or ice
Synonym: abrasionattritiondetrition
多通过句子记忆单词，而不是单独死记硬背。
