Polyethyleneimine
聚乙烯亚胺
🗣️ 情景例句
Don't ask why; just do as you are told.
别问为什么， 按要求去做就行了。
It takes a bit of nerve to cross these chain bridges.
过这种铁锁桥需要有点胆量才行。
Many young girls dream of being a fashion model.
许多年轻女孩梦想成为时装模特儿。