Sarah decides to move to Hainan because she thinks that the air there is much fresher than

问题补充：

Sarah decides to move to Hainan because she thinks that the air there is much fresher than here.

A. one

B. those

C. ones

D. that

答案：

A. one

B. those

C. ones

(答案→)D. that

解析：考查代词用法。One指代可数名词单数，表泛指；ones指代可数名词复数，表泛指；that指代不可数名词或者可数名词单数，后面必须有定语修饰，是特指；those指代可数名词复数，是特指。句意：Sarah决定搬去海南，因为她认为那里的空气要比这里的空气新鲜得多。