句中为什么this 要换成it?Rumor has this that there will be a strong e

这种用法就是it代表后面的从句.
主语常用：rumor, myth, legend, joke等
Rumor has it that her husband has gone overthe hill.
谣传她丈夫偷偷地离开了.
Oysters. Myth has it that oysters are thefood of love.
牡蛎有传说提到牡蛎是爱的食物,这是有科学依据的.