영어 문장에서 it과 they가 가리키는 것은?

1. “The shocking thing about this story is that it is not about snowmelt at the Arctic”에서 it은 무엇을 가리키나요?
2. “grain fed cattle were essentially reverse protein factories because they required many more pounds of plant protein”에서 they는 무엇을 뜻하나요?