过去分词放句首，不是被动语态，是非谓语动词
①Being+动词过去分词 ：
Being interviewed ，he felt very nervouse .
②done放在句首时表示：被动语态的，完成时态
如：
Seen from the top ，the building is very high .
worn out after a long walk ，he felt very tired .
③Having done 放在句首表示该动作与主句的主语是主动关系且强调该动作发生在主句谓语动作之前.
如：
Having finished his work ，he went home happily .
被动结构在句子中做谓语的时候，固定搭配是：be+done，这种情况下be动词不能省略。例如：
The books were read by Tom.
当被动结构在句子中做定语或状语的时候，不必加be动词。例如：
This broken glass is mine. (broken作定语)
Killed in a car accident， he never got to know how much I loved him. (killed by a car accident作状语)
