I’m moving to the countryside because the air there is much fresher than in the city.A. o

问题补充：

I’m moving to the countryside because the air there is much fresher than in the city.

A. ones

B. one

C. that

D. those

答案：

A. ones

B. one

(答案→)C. that

D. those

解析：That代替上文出现过的同类单数可数名词或不可数名词。 One代替上文出现过的那一个单数可数名词或不可数名词。