变被动句,主动句：They laugh at the little boy.注意动词的时态（laugh是原型，laughed是过去式）我不解的是既然是原型，为何无be动词？

变被动句,主动句：They laugh at the little boy.注意动词的时态（laugh是原型，laughed是过去式）我不解的是既然是原型，为何无be动词？ 英语主动句变被动句,和方法 主动句怎样变被动句求答案 They have finished their work主动句改为被动句 被动句改为主动句the door was knocked at while they were talking in the room改为主动句 怎样被动句变主动句?是 被动 变 主动!还有,请解释清楚怎么变的,思路清晰,格式明了! 用英语八种时态and情态动词 主动句变被动句造句 每种造两个句子要有主动句 和被动句 被动句变主动句.Potato chips were invented by mistake. 英语主动句改被动句题, 谁能告诉我10句主动句变被动句的句子原句和改动的句子都要有, 英语：主动变被动,被动变主动. 被动句子改成主动句 怎么改 被动句子改成主动句 怎么改 求初中英语——主动句变被动句的具体解析和例句本人在读初三,对主动句变被动句不慎了解,希望各位大哥大姐帮帮小弟,在此小弟先谢谢了!～～～～～～～～～～～ 主动变被动They often play football after school帮帮忙 they were saved by the clever cat被动变主动 主动句People use knives for cutting things变成被动句怎么变?knives _______ _______ for cutting things You mustn't laugh at others 改为被动句