请教一道08笔记里的题，关于虚拟语气的

cyrann

239. (GWD-12-Q3)
Were it not for the fusion-powered heat and radiation that rush from its core, instead its own weight would cause a star to collapse.
A. instead its own weight would cause a star to collapse
B. instead a star would have collapsed under its own weight
C. a star would have to be collapsing under its own weight
D. a star would collapse under its own weight
E. its own weight would have caused a star’s collapse
答案我没有问题。但解释里说从句里的it指代的是主句里的主语，这里不太明白。因为我看到很多句子主语是人、是复数等等，从句里也都是it啊。所以这个it到底应该怎么解释呢？谢谢~

rustraff

it是哪个it?从句里没有it

cyrann

rustraff 发表于 2016-6-6 14:55
it是哪个it?从句里没有it

Were it not里的it

rustraff

it were not for...that ,因为虚拟语气而产生的倒装