over 副词,结束,用法是：
sth is over （be有各种形式）：.完了、结束了,一般后面不跟宾语.
如,The match is over.
比赛结束了.
Jim has been over his homework 最好改为：
"Jim‘s homework has been over",and he is free now
=Jim has finished doing his homework already.He is free now
希望不要介意挑刺,）