Fd50
[醫] 半數致死量
??? 情景例句
He doesn't enjoy going to school.
他不喜歡上學。
I turned off when they started talking about computers.
當他們談論計算機時，我失去了興趣。
What's the matter, Granny? Can I help you?
什么事，老大娘？我能幫你嗎？