Polycations
(polycation 的复数) 聚阳离子
🗣️ 情景例句
the places they visit, and the landmarks.
他们所去的地方， 以及地标等等。
I worked at the shipping company this morning.
我今早在船公司工作。
So was born the echo-sounding apparatus, now in general use in ships.
这样就产生了目前各种船舶上普遍应用的回声探测仪。