请教prep新里几道题的思路，就要考了，请大家帮忙看一下吧

aaronjoqd

95.    (28538-!-item-!-188;#058&002980)查

Which of the following most logically completes the passage?
Using new detection techniques, researchers have found trace amounts of various medicinal substances in lakes and rivers.  Taken in large quantities, these substances could have serious health effects, but they are present in quantities far too low to cause any physiological response in people who drink the water or bathe in it.  Nevertheless, medical experts contend that eliminating these trace amounts from the water will have public health benefits, since A__E________.
A. some of the medicinal substances found in lakes and rivers are harmless to humans even if taken in large quantities
B. some of the medicinal substances found in lakes and rivers can counteract possible harmful effects of other such substances found there
C. people who develop undesirable side effects when being treated with medicines that contain these substances generally have their treatment changed
D. most medicinal substances that reach lakes or rivers rapidly break down into harmless substances
E. disease-causing bacteria exposed to low concentrations of certain medicinal substances can become resistant 有抵抗力的to them

82.    (33511-!-item-!-188;#058&007598)查

Technological improvements and reduced equipment costs have made converting solar energy directly into electricity far more cost-efficient in the last decade.  However, the threshold 门槛；开始of economic viability 生存能力；发育能力for solar power (that is, the price per barrel桶 to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars.
Which of the following, if true, does most to help explain why the increased cost-efficiency of solar power has not decreased its threshold of economic viability?c
A. The cost of oil has fallen dramatically.
B. The reduction in the cost of solar-power equipment has occurred despite increased raw material costs for that equipment.
C. Technological changes have increased the efficiency of oil-fired power plants.
D. Most electricity is generated by coal-fired or nuclear, rather than oil-fired, power plants.
E. When the price of oil increases, reserves of oil not previously worth exploiting become economically viable.

107.    (31025-!-item-!-188;#058&005951)    (GWD-TN-12,T-4-Q2)查

Twenty years ago, Balzania put in place regulations requiring operators of surface mines to pay for the reclamation再生；改造；开垦 of mined-out land.  Since then, reclamation technology has not improved.  Yet, the average reclamation cost for a surface coal mine being reclaimed today is only four dollars per ton of coal that the mine produced, less than half what it cost to reclaim surface mines in the years immediately after the regulations took effect.
Which of the following, if true, most helps to account for the drop in reclamation costs described?BC
A. Even after Balzania began requiring surface mine operators to pay reclamation costs, coal mines in Balzania continued to be less expensive to operate than coal mines in almost any other country.
B. In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.
C. Mine operators have generally ceased终止；结束 surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.
D. Even after Balzania began requiring surface mine operators to pay reclamation costs, surface mines continued to produce coal at a lower total cost than underground mines.
E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.
看了好几遍没弄清逻辑关系，生词都查出来了，希望大家帮帮里一下思路o(∩_∩)o...

BLinging

95题看懂了，也费了不少时间，是这样的思路：

题干里说，首先在河里检测出微量药物。这个药物呢，多了不好，有害；少了没什么关系。专家就说啦，这个药物最好没有。问为啥。

（答案一定要选微量药物也有害的选项）

A.和原文的条件都违背的，肯定不对
B.是说药物好的，错
C.和河里的药物根本没关系，转到people治疗上了，是无关选项
D.是说药物不好的，但是有点迷惑，但是没提量的问题，之前说是量大了才有问题
E.是说有这种物质的存在，即便少量，也会导致致病菌的抗药性，是符合题目逻辑要求的。

aaronjoqd

非常非常感谢楼上，懂啦~~~期待其他题目的解答~~~

aaronjoqd

自己又想了一下，剩下两题的思路是不是这样的啊，请大家帮忙指正一下：
82.新技术使太阳能转化为普通电能更加高效，但是太阳能转化产业的门槛价格却没变，问为什么
新技术也使得燃油工厂的效率提高了，但是由于门槛价格的设立是为了让太阳能行业比燃油行业更加盈利，所以门槛价格没有降低
107.B地要求煤炭开采者未开采过的每天支付改造费，但是现在改造费下降了，问原因：
开采者结束了对山区煤田的开采，因为哪里的改造费太高。这样就降低了平均费用。