Electric utilities pay less for low-quality coal per ton delivered than for high-quality coal. Yet more low-quality coal than high—quality coal must be burned to generate the same amount of electricity. Moreover, per ton of coal burned, low-quality coal generates more ash than does high-quality coal, and the disposal of ash is becoming more and more expensive.
The considerations above, if true, most strongly support which of the following claims?
A coal-burning utility might not be assured of benefiting economically by always adhering to the policy of keeping its overall coal purchasing costs as low as possible.
In those regions where the cost of disposing of coal ash is negligible, it is more expensive for coal-burning utilities to use high-quality coal than low-quality coal.
Transportation costs represent a smaller proportion of the cost per delivered ton for low-quality coal than for high-quality coal.
It is no less expensive to dispose of a ton of coal ash that results from the burning of high-quality coal than it is to dispose of a ton of coal ash that results from the burning of low-quality coal.
In regions where coal-ash disposal is the least expensive, reserves of low-quality coal are likely to decline at a faster rate than are reserves of high-quality coal.
低质量的煤每吨价格低于高质量煤的每吨价格;生产相同的电量,需要的低质量煤的质量要高宇高质量的煤。
单位体积的低质量煤所产生的灰比等体积的高质量的煤产生的灰尘更多,而且现在灰尘处理越来越贵。问must be true
choice a, 通过保证采购最低价格煤矿的策略,并不能保证这种方法在经济上最优的。correct
choice b, 在灰尘处理成本可以忽略不计的地方,使用优质煤比使用低质煤更加昂贵。incorrect, 无法得到生产相同的电量,低质量煤的价格和高质量煤的价格比较关系
choice d, 处理高质量煤产生的一吨灰的成本,并不比处理低质量煤产生的一吨灰的成本更便宜。incorrect,原本没有提及同等体积的灰尘处理成本关系
题目支持选项 注意题目中的信息
手打 一下官方解释。。。。:
A: CORRECT. the information presented dose not clearly support a conclusion about whether it's economically beneficial for coal-burning utilities to minimize their coal-purchasing costs. Therefore, utilities relying solely on this information cannot be assured that it is. 我的理解:各类费用具体的临界值不知道,是无法得出确切的选择方案的,所以正确答案说的是might(可能)。
The considerations above, if true, most strongly support
d根本稳重没提到,无关选项。。一定要和文中主旨有关系,而不是单纯脑补正确的无关选项
低质量煤比高质量煤每吨运送便宜
发相同电,低质量煤需要烧的比高质量煤多
低质量煤渣比高质量多,处理费在变得越来越贵
前面都是废话,最后越来越贵才是重点!!
题目倒是很耐心的读完了 大致意思也理解到了 但是没有注意细节
一定要注意边读边总结!!
前提①:产生相同amount的electricity花费的低质量coal比高质量多。
前提②:低质量coal产生更多的ash,处理ash越来越贵==》more and more有点在暗示最红有一天处理ash的花费会超过购买低质量coal所带来的成本节约
一定要读懂每一个选项啊!!!不要盲目快进!!读完每一个选项之后仔细的去思考一下!!
文字游戏,因为低质煤单价虽然低,用量更多,所以购买没得总成本谁高谁低压根不知道;所以这题实际上所有总成本都不知道,任何可能性都有,所以只要答案包含可能二字的,都可以选。事实上,如果A选项把might去掉,A-E全部都推不出来。
重点在the disposal of ash is becoming more and more expensive,所以只用低质煤会使成本越来越高
A的意思其实是一直采用尽可能降低购买成本的公司现在不能保证像以前一样获利了。(降低购买成本可以极端理解为全买最便宜的低燃烧率煤+更高的煤灰处理费=原利润下降)
B错在 不知道quantity,只有price的对比是不能知道 total cost的大小的
这题是默认了便宜的coal质量就差吗?要不是排除了bcde我也不太敢选a
抱歉哈各位 打出来了一堆字 又没有了。。。总结而言,A。看见不确定放下先。B错,因为TC=P*Q+Cd,C错,因为out of scope。D,事实上题目没有告知Cd的具体情况,不能推断。E错,如果reserve下降的意思是想说人们会用L多一些的话,前面已经说明了影响人们使用的是最终的TC。Cd只是其中一个inf因素。
为什么不见了一堆字。。。
pl
這題做錯了。
重新考察題目,發現幾個變量。分別為Cost of disposal(Cd),Qof ash(Qa),Quantity to burn(Qb),Energy generated(E)。有stimulus可知:
Qal>Qah if Qbl=Qbh; Cd(per ton) both Unknown; Qbl>Qbh if El=Eh. Btw Pl
A中隐含了购买高质量煤炭比低质量煤炭成本更高的条件。这种算常识吗?
这是一个靠翻译取胜的题。
感觉没什么方法啊,求教老师!!
演绎