Sourcebook
n. 原始资料(集),资料读物
🗣️ 情景例句
I don't know about that.
我表示怀疑。
To tell you the truth that.
老实说。
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。