sit in 和sit on 有什么用法和区别、?

sit in 和sit on 有什么用法和区别、? sit in his seat.为什么用in,平时不是sit on吗 用on和用in有什么区别? sit on 和sit at的区别 sit on 和sit down的区别 sit at desk 和sit on the desk有什么区别 sit和seat用法区别 sit around 和sit back 有什么区别 sit at the corner和sit in the corner 有什么区别吗?是否可以互换 sit in,sit on,sit at,sit down的区别 seat和sit有什么区别? sit in a chair sit on区别 sit in 与sit on 的区别?