Trephining
[医] 环钻, 环锯
🗣️ 情景例句
If you don't know a person's last name, use 'ma'am' or 'sir'.
如果你不知道一人的姓， 你应称呼他为 'ma'am' 或 'sir' 。
My uncle had a heart attack last year.
我的叔叔去年患了心脏病。
I'm afraid that he'll forget it if he misses so many lessons. He may even fail his Chinese exam.
如果他再缺这么多课，恐怕他会忘记很多的。他的汉语考试甚至会不及格。