Polyethyleneimine
聚乙烯亚胺
🗣️ 情景例句
Consider the cost before you decide.
你决定前要先考虑费用问题。
This is a record player.
这是一台电唱机。
My holidays passed quickly, but I did not send cards to my friends.
假期过得真快，可我还没有给我的朋友们寄过一张明信片。