GWD-8-Q21，请ＮＮ指点

云的足迹

Last year all refuse collected by Shelbyville city services was incinerated.  This incineration generated a large quantity of residue ash.  In order to reduce the amount of residue ash Shelbyville generates this year to half of last year’s total, the city has revamped its collection program.  This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year’s number. 

 

Which of the following is required for the revamped collection program to achieve its aim?

 

A.       This year, no materials that city services could separate for recycling will be incinerated.

B.        Separating recyclable materials from materials to be incinerated will cost Shelbyville less than half what it cost last year to dispose of the residue ash.

C.        Refuse collected by city services will contain a larger proportion of recyclable materials this year than it did last year.

D.       The refuse incinerated this year will generate no more residue ash per truckload incinerated than did the refuse incinerated last year.

E.        The total quantity of refuse collected by Shelbyville city services this year will be no greater than that collected last year.

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 答案是Ｄ，我选Ａ了，题目里不是说目标是减少到一半么，Ｄ里假设没个ＴＲＵＣＫ的转载都比原来少，那不一定是少到一半了啊，不太明白，请ＮＮ指点一下

云的足迹

上面的太小了，再发一下，黑黑

Last year all refuse collected by Shelbyville city services was incinerated.  This incineration generated a large quantity of residue ash.  In order to reduce the amount of residue ash Shelbyville generates this year to half of last year’s total, the city has revamped its collection program.  This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year’s number. 

 

 

Which of the following is required for the revamped collection program to achieve its aim?

 

 

A.       This year, no materials that city services could separate for recycling will be incinerated.

B.        Separating recyclable materials from materials to be incinerated will cost Shelbyville less than half what it cost last year to dispose of the residue ash.

C.        Refuse collected by city services will contain a larger proportion of recyclable materials this year than it did last year.

D.       The refuse incinerated this year will generate no more residue ash per truckload incinerated than did the refuse incinerated last year.

E.        The total quantity of refuse collected by Shelbyville city services this year will be no greater than that collected last year.

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 答案是Ｄ，我选Ａ了，题目里不是说目标是减少到一半么，Ｄ里假设没个ＴＲＵＣＫ的转载都比原来少，那不一定是少到一半了啊，不太明白，请ＮＮ指点一下

kevinli120

文章结尾说通过recycle减少要焚烧垃圾的truckloads到去年的一半，以减少产生的ash到去年的一半。

产生的ash的量 = number of 要焚烧垃圾的truckloads * 每truckloads产生的ash量

number of 要焚烧垃圾的truckloads 已经减少到去年的一半了，要想产生的ash的总量为去年的一半，必须要求就是per truckloads 产生的ash量不会比去年多。否则，每truckloads要焚烧的垃圾产生的垃圾量为去年的100倍，减少一半truckloads也无济于事

wxsimon

D确实更具说服力，那A错在哪儿呢？

减少truckload的方法是recycle，烧truckload里装的refuse占一半，需要recycle的refuse占一半，那如果recycle的那一半也有一部分拿来烧（A取非），那么这个total ash的量会怎么样呢？是不是A不能确定到底是会增多还是会减少才不选的？

没办法1987

Last year all refuse collected by Shelbyville city services was incinerated.  This incineration generated a large quantity of residue ash. 
                In order to reduce the amount of residue ash Shelbyville generates this year to half of last year’s total, the city has revamped its collection program.  This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year’s number. 

Which of the following is required for the revamped collection program to achieve its aim?假设

此题为：方法——>目的 型。判断的标准是“该方法是否能达到目的”  目的仅为“reduce the amount of residue ash ”

A.      This year, no materials that city services could separate for recycling will be incinerated.

A主要错在“不必要”，no materials 太强烈了，取非：some materials will be incinerated 还是会达到目的：会减少灰尘

D.      The refuse incinerated this year will generate no more residue ash per truckload incinerated than did the refuse incinerated last year.

取非，削弱

wxsimon

以下是引用没办法1987在2009/9/18 10:20:00的发言：

Last year all refuse collected by Shelbyville city services was incinerated.  This incineration generated a large quantity of residue ash. 
    In order to reduce the amount of residue ash Shelbyville generates this year to half of last year’s total, the city has revamped its collection program.  This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year’s number. 

Which of the following is required for the revamped collection program to achieve its aim?假设

此题为：方法——>目的 型。判断的标准是“该方法是否能达到目的”  目的仅为“reduce the amount of residue ash ”

A.      This year, no materials that city services could separate for recycling will be incinerated.

A主要错在“不必要”，no materials 太强烈了，取非：some materials will be incinerated 还是会达到目的：会减少灰尘

D.      The refuse incinerated this year will generate no more residue ash per truckload incinerated than did the refuse incinerated last year.

取非，削弱

取非，削弱

弱问，a取非，some materials that city services could separate for recycling will be incinerated。 incineration会产生ash，那么本来是recycle不产生ash的现在拿来烧就产生了ash，达不到减少至一半的目的啊，总的ash会比现在的一半多一点。。

cyr93

为什么不能选C呢

InfiniteAlex

很赞，谢谢

Olivia2Chicargo

stem:  

Last year,
all refuse(N truckload)--->incinerated--->ash

This year,

All refuse --- separate for recycling ---> refuse to be incinerated (resulting in half the previous year's truckloads N/2) ---- incinerate this left over refuse ----> ash (which is half the last year's quantity)

Therefore, this year only half the amount of ash is being incinerated. So, ttl refuse for incineration= truckloads numbers* the ash per truck load.  So, unless each truckload generates less residue ash than it did last year, the objective cannot be achieved.


排除 AC 的关键是 half of last year.  AC 都可以起到作用， 但是由于缺乏具体数据支持， 无法证明可以减少一半。


这是道 assumption 的问题， 也就是必要条件， 如楼上所说也是个 方法到目的的问题， 这个题的点就是补上从half number of truckloads 到 half amount of ash 的 gap, 那就是 每车的ash amount 不比去年多。

huihlin

kevinli120 发表于 2009-8-8 13:08
文章结尾说通过recycle减少要焚烧垃圾的truckloads到去年的一半，以减少产生的ash到去年的一半。产生的ash ...

同意！