关于指示代词的问题~~~~~~~

题目

关于指示代词的问题~~~~~~~
1.The blackboard of classA is cleaner than _____ of classB.
A. that B. the one
2.The windows of classA are cleaner than _____ of classB.
A. those B. the ones
求原因~

答案

1.A
2.A
解析：that指代前文提到的有定冠词修饰的可数名词单数或者不可数名词；those指代前文提到的有定冠词修饰的可数名词复数.而且这俩代词往往跟of短语作后置定语.而the one/the ones的定语一般是前置的,如the red one/the right ones.