sit in for 是一个词组么?原句是 millions of college students sit in fo

sit in for 是一个词组么?原句是 millions of college students sit in fo sit in,sit on,sit at,sit down的区别 是sit on the chair还是sit in the chair 是sit in a chair还是sit on a chair? 是sit in the sofa 还是sit on the sofa? 是sit in the armchair还是sit on the armchair? 一个小小的英语问题：students learn their lessons in class.they sit in She ()(sit)in front of the computer. （十万火急）英语题There are lots of students ____(sit) in the office 关于sit-in student sit in a boat we sit lines in