__experiments on the laboratoy,it started to rain heavily.A,while performing B,performing C,while i was performing D,to performABD为什么不对?求详解...

问题描述:

__experiments on the laboratoy,it started to rain heavily.
A,while performing B,performing
C,while i was performing D,to perform
ABD为什么不对?求详解...

ABC,从句主语省略,那么从句的主语就应该是it ,指天气,而it 和 perform没有动宾关系,所以从句的主语必须是人,只有C是人做主语,选C.
希望能够帮到你哦!