新概念二册61课第二句The main mirror was faulty,so the pictures it sent us were very disappointing

题目

新概念二册61课第二句The main mirror was faulty,so the pictures it sent us were very disappointing
请问为什么会有It 如果没有so the pictures sent us were very disappointing.不也可以吗

答案

it 在这里指代的是mirror,
it sent us 是一个定语从句,修饰pictures,
去掉定语从句就是,so the pictures were very disappointing.
所以,it 不能没有,除非你把整个定语从句去掉.
后一句的意思,是说镜子发送给我们的图片令人非常失望,it在这里强调镜子mirror,也就是the main mirror,这样前后两句话才相互对应上了.