点击下方单词,选择对的这个单词
ph.
1. become more focus on an area of activity or field of study
e.g. She specializes in Near Eastern history
Synonym: specializespecialisenarrow
2. define clearly
e.g. I cannot narrow down the rules for this game
Synonym: pin downpeg downnail downnarrowspecify
多通过句子记忆单词，而不是单独死记硬背。
