Prebiotic
a. 生命起源以前的
🗣️ 情景例句
By this time next week we shall be in London.
下星期的这个时间我们将在伦敦。
That's easy for you to say.
你说的容易。
Good afternoon, class! Who's on duty today?
同学们，下午好！今天谁值日？