主动语态转化被动语态.I have been to america twice.

主动语态转化被动语态.I have been to america twice. 被动语态改为主动语态 主动语态变被动语态 I have told the children many times not to skate on the pond.急 主动语态变被动语态练习题 英语主动语态怎么改成被动语态 由主动语态变为被动语态 被动语态与主动语态区别 被动语态和主动语态的区别 被动语态变主动语态怎么变 被动语态怎样变主动语态? 英语 将主动语态改为被动语态 主动语态怎么变被动语态 如何区分主动语态与被动语态 把主动语态改成被动语态 如何区分主动语态和被动语态. 德语把主动语态改为被动语态 如何区分主动语态和被动语态. 如何将主动语态改为被动语态?