Nicotyrin
雪茄堿; 煙堿烯; 二烯煙堿
??? 情景例句
How do you feel about this?
你覺(jué)得呢？
I've already read that book.
我已經(jīng)讀了那本書(shū)。
But the historian attempting to reconstruct the distant past is always faced with a difficult task.
但是，歷史學(xué)家企圖重現(xiàn)遙遠(yuǎn)的過(guò)去可是一項(xiàng)艱巨的任務(wù)，