Polycation
聚阳离子
🗣️ 情景例句
Mary, this is Stone's brother Jim.
玛丽，这是世通的兄弟吉姆。
What time is it now?
现在几点？
I never heard of anyone making a'skeleton', as we were taught at school.
我从未听说过任何一位作家像我们在学校学的那样，动笔前先列什么提纲。