Mr.Green is said _____ an experiment to prove the new method of solving the problem when young.为什么不能填to do呢?为什么有了when young就要用完成的形式?求讲解

This is Mr Green Mr Green’s T-shirt is white,and Mrs ___ green.选哪个?A.Green’s B.Green is C.Greens’ D.Green’s is Mrs.Green is from England.Mr.Green is from England,too(同义句)Mrs.Green,____ ____ ____ Mr.Green ___ from America.I have lived here for five years.(for five years提问)How ___ ___ ___ ___ here? mr.green is mrs.green is （ ） an American writer,Mr Green once said. It is said that Mr Green will be away for a few days.为什么用will? the station is lively Mr Green said(.)将句子合并为含有宾语从句的复合句 Is Mr.Green from the USA = ___ Mr.Green ___ from the USA 这道题我想了很久也没想出来 Is mr green your u_____? Mr Green left China last week.Mr Green ____ ___ ___ ___ China since last week. This is Mr Green's room.Mr green's画线 My English teacher is Mr Green.对Mr Green提问 Mr.Green is a good worker.He has rich ___ (经验)because he has had lots of working ___(经历). She told me____her teacher.A Mr Green isB that Mr Green is C if Mr Green wasD Mr Green was Mr.Green is used to____(work) hard. Is Mr Green English?作否定回答 that man is Mr.green.怎么提问 Mr Green is very _______(excite)