求讲解被动语态我不知道被动语态句子该如何理解 eg：this book is designed for the youn

求讲解被动语态我不知道被动语态句子该如何理解 eg：this book is designed for the youn 被动语态讲解如何引入 Is this book is written by Bill Gates 到底是用is还是was 我知道是被动语态 讲解被动语态, 被动语态的讲解 LuXun wrote this book 改为被动语态 句子改成被动语态 they don't read the book WHo is the author of this book 将这句话变成被动语态! who designed this kind of machine?改为被动语态 help~ You can keep the book for two weeks .改为被动语态的句子啊什么啊? 求大神给我讲解一下英语中的被动语态. the designer designed the casual clothes改为被动语态