Unit 3一、知识点英语有两种语态:主动语态和补动语态主动语态表示是动作的执行者被动语态表示主语是动作的承受者Catseatfish.(主动语态)猫吃鱼。Fish is eaten by cats. (被动语态 )鱼被猫吃。被动语态的构成由“助动词 be 及物动词的过去分词”构成助动词 be 有人称、数和时态的变化,其变化规则与be 作为连系动词时完全一样。时态被动语态结构例句一般现am /is/are + 过去分词English isspoken in在 时many countries.一般过was +过去分词This bridge was built in去 时were + 过去分词1989.情 态can/shouldThe work must be donemay +be+过去分词动 词right now