改被动语态He was doing his homework at this time yesterday .He was doing his homework at this time yesterday .--His homework was being done by him at this time yesterday ...为什么不能改成His homework was done by him at this time yesterday

I saw him going to the office .的被动语态怎么改?是He was seen to going to the offi...I saw him going to the office .的被动语态怎么改?是He was seen to going to the office.感官动词接doing的被动语态形式怎么改? 改被动语态改被动语态 He speak EnglishShe wrote a bookWe make watches in China 改被动语态He was doing his homework at this time yesterday .He was doing his homework at this time yesterday .--His homework was being done by him at this time yesterday ...为什么不能改成His homework was done by him at this time yesterday He said he would make a kite 改被动语态 改被动语态 he took a blue suitcase to beijing改被动语态 did he made you do this改被动语态 he does his homework every day如何改被动语态 He cleans the room every Sunday（改被动语态） He can repair the bike.(改被动语态)快 谢 He gave me a gift.怎么改被动语态? he plays basketball after school every day (改被动语态) he often listens to music改被动语态 He didn't throw the bad food.改被动语态, He broke the window yesterday（改被动语态） 改被动语态：He keeps salt in the cupboard 英语改被动语态：he gave me apresent .书上改为被动就是I was given apresent .我想问的是,它的被动形式为什么不是：I was gave a present . 帮忙解题 改被动语态