Fd50
[医] 半数致死量
🗣️ 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。
I hope I'm not in the way.
我希望没有造成妨碍。
A short time before, great trees had covered the countryside for miles around.
就在不久之前，参天大树还覆盖着方圆数英里的土地。