Perthiocarbonate
过硫碳酸盐
🗣️ 情景例句
No one knows for certain what happened, but it's a fair bet that it was not an accident.
没有人知道究竟发生了什么，但几乎可以肯定这并非意外。
Fair faces need no paint.
貌美毋须修饰。
What is it?
什么困难。