Perfected
v. 使…完美, 使…熟练（perfect的过去形式）
✅ 同义词
🗣️ 情景例句
Ask Paul Smith to fill in for me.
叫Paul Smith代替我出席。
The telephone is ringing,would you answer it,please?
电话正在响,你接吗？
below 20 per cent, its bactericidal action is negligible.
浓度低于20％时，杀菌能力基本上就不存在了。