be done用于被动语态
之所以是being 是因为前面有个介词（介词后动词用ing形式）
希望你能理解 不懂还可以继续问.那么这句"It is being repaired by a friend of my father's"中“is”也不是介词啊，为什么也用“being”呢？系动词am is are后面要用ing形式。这个…你应该是懂得吧…a friend of my father repair it .It is repaired by a friend of my father.为了表示进行时态所以it is being repaired by a friend of my father.希望你能理解。被动语态的题做多了就不难了。刚开始还是会有一点混。加油