单选题 .  California has been facing a drought for many years now, with certain areas even having to pump freshwater hundreds of miles to their distribution system. The problem is growing as the population of the state continues to expand. New research has found deep water reserves under the state which could help solve their drought crisis. Previous drilling of wells could only reach depths of 1,000 feet, but due to new pumping practices, water deeper than this can now be extracted (抽取). The team at Stanford investigated the aquifers (地下蓄水层) below this depth and found that reserves may be triple what was previously thought.
    It is profitable to drill to depths more than 1,000 feet for oil and gas extraction, but only recently in California has it become profitable to pump water from this depth. The aquifers range from 1,000 to 3,000 feet below the ground, which means that pumping will be expensive and there are other concerns. The biggest concern of pumping out water from this deep is the gradual settling down of the land surface. As the water is pumped out, the vacant space left is compacted by the weight of the earth above.
    Even though pumping from these depths is expensive, it is still cheaper than desalinating (脱盐) the ocean water in the largely coastal state. Some desalination plants exist where feasible, but they are costly to run and can need constant repairs. Wells are much more reliable sources of freshwater, and California is hoping that these deep wells may be the answer to their severe water shortage.
    One problem with these sources is that the deep water also has a higher level of salt than shallower aquifers. This means that some wells may even need to undergo desalination after extraction, thus increasing the cost. Research from the exhaustive study of groundwater from over 950 drilling logs has just been published. New estimates of the water reserves now go up to 2,700 billion cubic meters of freshwater.1.  How could California's drought crisis be solved according to some researchers? ______
【正确答案】 B
【答案解析】 加利福尼亚州如今已多年面临干旱问题，某些地区甚至不得不从数百英里外将淡水抽运至其供水系统。随着该州人口的持续增长，干旱问题也逐步加剧。一项新研究发现，加州地底下有深层蓄水，这可以帮助解决其干旱危机。以前的钻井深度只能达到1000英尺，但采用新的抽水技术后，现在可以抽取更深的水资源。斯坦福大学的研究小组调查了深度1000英尺以下的地下蓄水层，发现储量可能是此前预计的三倍。
   钻探超过1000英尺的深度去开采石油和天然气颇有盈利，但在加州，从这个深度抽水变得有可利图只是最近的事。地下蓄水层位于地下1000至3000英尺处，这意味着抽水将耗费巨资，同时还伴随着其他令人担忧的问题。从这个深度抽水的最大问题是地表会逐渐下陷。因为水被抽出后，留下的空间受上面土壤的重压而缩减。
   尽管从这个深度抽水十分昂贵，但它仍比大部分面积位于沿海的州所采用的海水淡化方式要便宜。在条件允许的地方也有海水淡化厂，但其运营成本高，且需要不断维修。水井是更加可靠的淡水来源，加州人希望这些深水井可解决其严重的水资源短缺问题。
   这些资源存在一个问题，即深层水的含盐量高于浅层水。这意味着，从深水井中抽取的水甚至可能需要脱盐淡化，因而增加了成本。一份刚发表的研究全面调查了950多个钻井记录，预估当前的淡水储量多达2.7万亿立方米。
   根据题干中的California's drought crisis和solved定位至第1段。
   题目询问一些研究人员认为加州的干旱危机可以通过什么方式解决。第1段第3句中提到，这可以帮助解决干旱危机(which could help solve their drought crisis)，由此可见，解答本题的关键在于找出which指代的内容。通过分析句子成分可知，which从句修饰deep water reserves“深层蓄水”，即which指代“深层蓄水”，由此可知，抽取深层蓄水是解决加州干旱危机的方式，故选B“抽取地下深层蓄水”。
   A是利用文中reserves制造的干扰项，第1段最后一句仅提到，斯坦福大学的研究小组发现1000英尺以下的地下蓄水层储量比之前预估的高，A“通过储备更多地下水”曲解文意，且答非所问，故排除。原文并未提及drilling devices“钻井设备”，据此排除C“通过开发更先进的钻井设备”。文章首句提到了distribution system“供水系统”，但此处要说明的是某些地区旱灾的剧烈程度：不得不从数百英里外将淡水泵入其供水系统，据此无法得出D“升级供水系统”是解决干旱危机的方式，故也排除。