it和that的区别

题目

it和that的区别
The air in the countryside is much fresher than______.
A.the city B.in the city
C.that in the city D.it in the city

答案

选C.
1.that用来指代前文出现的不可数名词或特指的可数名词单数（不特指的可数名词单数用one）,这里用来指代空气这个不可数名词.
2.that指代的是同一类东西,这道题里是乡下的空气和城里的空气,不是同一样东西.而it指的是同一个东西.比如：I bought a book yestery.It is interesting.