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
网友回答
A. ones
B. one
(答案→)C. that
D. those
解析：该题考查代词的用法。that 代替前边出现过的词,应该有后置定语,即:比较的对象是the air there和the air in the city。that 代替前边出现过的the air。