1.The most interesting books are not necessarily--with a lot

1.The most interesting books are not necessarily__with a lot of pictures.A.these B.the ones C.them D.that这个题的答案是：B,想知道ones的用法,这里为什么能用the ones来替代前面的books?2.The population of China is larger than__of any country.A.one B.the one C.that D.it 这个题的答案是：C,想知道为什么其他三个不可以?3.she went for a swim in the pool yesterday and I'll do __this afternoon.A.it B .such C.same D.the same 这题答案D；为什么A不行呢?it也可以指代前面的事情?暂时就这几个吧,都是比较基础的,个人英语水平比较差.