P. p. d.
[医] 精制蛋白衍化物(结核菌素)
🗣️ 情景例句
Look before you leap.
想好了再行动。
What kind of breakfast did you have?
你吃了什么样的早餐？
a ticklish business which is achieved with the aid of two tame elephants roped to the captive on either side.
这是一件棘手的事，需要在它两侧拴上两头驯服的大象才能完成。