在总结GWD，然后发现GWD-8-14和GWD-13-30是有一些点能相互印证的，所以我把两题拉出来放在一起比较一下，大家一起讨论哈～

GWD-8-Q41:

When drive-ins were at the height of their popularity in the late 1950’s, some 4,000 existed in the United States, but today there are less than one-quarter that many.

1. there are less than one-quarter that many

2. there are fewer than one-quarter as many

3. there are fewer than one-quarter of that amount

4. the number is less than one-quarter the amount

5. it is less than one-quarter of that amount

Q18 GWD-13-30
    ：For the first time in the modern era, non-Hispanic Whites are officially a minority in California, which amounts to a little less than half the population of the state, down from nearly there-quarters only a decade ago.

1. which amounts to a little less than half the population of the state, down from nearly three-quarters only a decade ago

2. which amounts to a little less than half the population of the state, down from a decade ago, when it was nearly three-quarters

3. and that amounts to a little less than half the population of the state, down from a decade ago, when they were nearly three-quarters

4. amounting to a little less than half the population of the state, down from nearly three-quarters a decade ago

5. amounting to a little less than half the population of the state, down from what it was a decade ago by nearly three-quarters

1） 对one-quarter /three quaters的用法：GWD8-41的 A C D E选项中，one quarter后面都是有内容的：

    A.one-quarter that many

    C.one-quarter of that amount

    D.one-quarter the amount

    E. one-quarter of that amount

只有B 中直接使用one quater，当时我想应该one quarter能够单独使用，如果后面的部分已经在前面部分出现过，那么one quater后面与前面相同的内容是可以省略的。(one-quarter后面省略了of the amount) 这个想法在GWD13-30的D 选项中得到证实。（three-quarters 后面省略了the population.）

但是如果one-quarter of 后面的内容之前没有出现过，是需要补出的。eg. One-quarter of the dogs are black.

2) 关于number和amount的用法：

在PREP官方答案出来以前，GWD-8-Q41的D选项一直是争议选项。但是我认为the number是不能当同位语来概括前面的数量的。 因为the number单独使用时会有其他的含义。比如：The number is busy now.（电话正忙）。但是amount就是单意词，指数量。所以如果要做前面的数量的同位语或者表达数量的含义时，因该使用amount。这点在 GWD-13-30 五个选项中都有体现。

1. which amounts to a little less than half the population of the state, down from nearly three-quarters only a decade ago

2. which amounts to a little less than half the population of the state, down from a decade ago, when it was nearly three-quarters

3. and that amounts to a little less than half the population of the state, down from a decade ago, when they were nearly three-quarters

4. amounting to a little less than half the population of the state, down from nearly three-quarters a decade ago

5. amounting to a little less than half the population of the state, down from what it was a decade ago by nearly three-quarters

1） 对one-quarter /three quaters的用法：GWD8-41的 A C D E选项中，one quarter后面都是有内容的：

    A.one-quarter that many

    C.one-quarter of that amount

    D.one-quarter the amount

    E. one-quarter of that amount

只有B 中直接使用one quater，当时我想应该one quarter能够单独使用，如果后面的部分已经在前面部分出现过，那么one quater后面与前面相同的内容是可以省略的。(one-quarter后面省略了of the amount) 这个想法在GWD13-30的D 选项中得到证实。（three-quarters 后面省略了the population.）

但是如果one-quarter of 后面的内容之前没有出现过，是需要补出的。eg. One-quarter of the dogs are black.

2) 关于number和amount的用法：

在PREP官方答案出来以前，GWD-8-Q41的D选项一直是争议选项。但是我认为the number是不能当同位语来概括前面的数量的。 因为the number单独使用时会有其他的含义。比如：The number is busy now.（电话正忙）。但是amount就是单意词，指数量。所以如果要做前面的数量的同位语或者表达数量的含义时，因该使用amount。这点在 GWD-13-30 五个选项中都有体现。