check in有过去式吗?

check-in check in有什么区别 手机check in agent和check in,qtmobility,qtwebkit,这四个是什么,可以删除吗,有 vss check in 和Undo check out 有什么区别 check in 和 check check in和check check in check out 和 check in vss2005 check in check out check和check for有什么区别吗? check in check out check up check with sign in 与 check in 用法有何不同? 请问“Guest had to show job card each time check in.”有语法错误吗?