你的问题中的being/ be /been是固定的,无需改变.你可以这样考虑.现在进行时的一般式为be +v-ing,在改成被动语态时必须同时符合符合进行时的基本结构,同时符合被动语态be+done,两者结合为be being done.前两个符合进...我开始有点理解了，你能给个举两个例子那就更好了还有情态助动词的被动语态也一样吗？1.We are building a new bridge.---A new bridge is being built( by us)2.We will plant more trees next year.---More trees will be planted next year.3.They had repaired five cars when I got there.---Five cars had been repaired when I got there.情态动词的被动语态原理一样。其实所有时态的被动语态都是同理。你很聪明！！祝你不断进步！！明白了再问一个，怎么区分to在句子中是介词还是不定式？有固定的结构依据吗？to后面加名词或动词ing的就是名词，加动词原形的就是不定式。这是语法规则，也是固定的结构依据吧。