Monosystem
单系
🗣️ 情景例句
They talk about things like family, work, school or sports.
他们常常谈论家庭，工作，学校或运动。
Where am I supposed to pay the excess train fare?
我应该在哪里补票？
It's very kind of you to help me.
你帮助我真是太好了。