that it 作指代的时候怎么区分

题目

that it 作指代的时候怎么区分
1.----what made more than 10000 people die?
-----________ the tsunami in the Indian Ocean.
A it was B that was
为什么不能选 B
2.my father is over sixty,but he doesn't look _____.
a it b that
为什么不能选 that

答案

1.it作代词指代导致10000人死亡的事件
2.it指具体的60多岁
that
指代前面提到的同类事物,可指代可数名词单数或不可数名词.是同类不是同一个.