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. (地势)走低,降低If land or ground drops away, it slopes down so that it is at a lower level to where you are or from a particular point that has been mentioned.
1. get worse
e.g. My grades are slipping
Synonym: slipdrop offfall away
多通过句子记忆单词，而不是单独死记硬背。
