Rarefying
v. 使稀薄( rarefy的现在分词 ); （思想等）精炼; 使纯化; 使变得精妙深奥
✅ 同义词
🗣️ 情景例句
I made an appointment with the doctor at three.
我和医生约好3点钟看病。
I'm afraid all my efforts were in vain.
我担心我的努力全白费了。
If you don't work, you will fail to pass the exam.
如果你不学习，你考试就会不及格。