When_____ that this was no ordinary fish,he tried not to damage it.
问题描述：
When_____ that this was no ordinary fish,he tried not to damage it.
a,realizing b,having realized c,he realized d,he has realized
我觉得每个答案都可以,为什么其他不对?
答
C
因为从句时过去时（tried)
所以前面也是过去时,时态一致
所以是c