Perhalogeno-
[化] 全卤(代)(代替所有C上的氢)
🗣️ 情景例句
I do some work for Smith and Dale,Your company's accounting firm.
我为贵公司的会计顾问公司 Smith和Dale事务所里做一些工作。
In college I majored in philosophy, What was your major?
大学时我主修哲学，你主修什么呢？
It can take as long as eight days to rig up rope ladders and to establish supply bases before a descent can be made into a very deep cave.
有时需要花费整整8天时间来搭起绳梯，建立供应基地，然后才能到一个很深的洞穴里。