.Nine in ten parents said there were significant differences

十分之九的家长说他们教育孩子的方法与父辈比较有很大不同
替代词that的用法
1.that作代词时表示特指,指代前面提到过的那类事物,即替代带定冠词的名词,既可用来替代可数名词的单数形式,也可用来替代不可数名词.如：
His seat was next to that of mine.
( that = the seat = the one )
I have quite a lot of homework to do.I must finish that first.
(that = quite a lot of homework to do,不能用the one替代,因为one替代的是可数名词的单数形式,而这里的homework为不可数名词)
2.that替代的是the+名词,one替代的是a / an+名词.
3.当前文中的名词为可数名词表示事物时,是使用that还是one来替代,取决于它们所在位置上是该使用带定冠词的名词还是使用带不定冠词的名词.在前一种情况下使用that,在后一种情况下使用one.如：
The book on the desk is newer than that on the shelf.
(that on the shelf 所替代的实际上是the book on the shelf,而不是a book on the shelf).
I’m looking for a house.Id like one with a garden.(one = a house)
4.that不可替代表示人的名词,而one却可以.
5.that只能带后置定语,it则没有修饰语,而one既可带后置修饰语,也可带前置修饰语.如：
The water in wells is cleaner than that in rivers.
Your plan is a good one on paper.
6.在比较状语从句中,两个相比较的成分必须对等.如果相比较的成分是名词,则后一比较项目中的名词可以用that（用来替代与前文同类的不可数名词）或those（替代与前文同类的复数可数名词）来替代.而在汉语比较句中,可以省略后一比较项相同的词语.如：
The weather today is colder than that yesterday.
（句中that代替the weather,在这里不能用it代替,也不能用the one代替,因为weather是不可数名词）
还可以表示为：The weather today is colder than that it was yesterday.
The things in a street market are cheaper than those in a supermarket.
(其中those不能用them代替,用those代替可数名词的复数是特指,可用the ones代替)
还可表示为：The things in a street market are cheaper than they are in a supermarket.