同学,很高兴回答你的问题
正确答案如下：
1.My mother has been ( cooking )since she came home.
2.The girl said hello to me ( politely ).
3.Jodie enjoys ( telling )jokes very much.
4.Cathy is ( interested ) in all the ( interesting ) things.(interedt)
5.It's necessary for you ( to eat )three meals a day
6.Jane didn't stop until she finished ( doing )all her work.
7.-- Could you please sweep the floor?-- ( Certainly ).
8.Nick got a camera on his ( ninth ) birthday.
9.Lisa has a great ball ( collection ).
10.Thanks for ( helping ) me find my little brother.
解析：
1,现在完成进行时,强调动作的持续进行
2.修饰动词用副词
3.enjoy doing sth.喜欢做某事,固定搭配
4.be interested in；对...感兴趣,interesting 令人感兴趣
5.it is necessary for sb.to do sth.对某人来说做某事有必要,固定搭配
6.finish doing sth.完成做某事
7.certainly 当然
8.第九个生日,用序数词
9.用名词形式,收藏,收集的意思
10.thanks for doing sth.介词后面用动名词形式.
有不明白的请继续追问,