Fd50
[医] 半数致死量
🗣️ 情景例句
How about a lemonade break?
休息一下喝点柠檬水好吗？
We're working fast to try and make up for lost time.
我们正加紧工作以争取补偿失去的时间。
So was born the echo-sounding apparatus, now in general use in ships.
这样就产生了目前各种船舶上普遍应用的回声探测仪。