46. What does the author say about the use of raw sewage for farming?
- A. Its risks cannot be overestimated.
- B. It should be forbidden altogether.
- C. Its benefits outweigh the hazards involved.
- D. It is polluting millions of acres of cropland.
答案：C
答案句：Facing water shortages and escalating fertilizer costs, farmers in developing countries are using raw sewage (下水道污水) to irrigate and fertilize nearly 49 million acres of cropland, according to a new report-and it may not be a bad thing. … While the practice carries serious health risks for many, those dangers are outweighed by the social and economic gains for poor urban farmers and consumers who need affordable food.
参考译文：面对水资源短缺和不断上涨的化肥成本，发展中国家的农民正在使用未经处理的下水道污水来灌溉和施肥近4900万英亩的农田，根据一份新报告——而这可能并非坏事。……虽然这种做法对许多人带来严重的健康风险，但这些危险被贫困城市农民和需要负担得起的食物的消费者所获得的社会和经济收益所抵消。
定位线索：题干“use of raw sewage for farming”→答案句“farmers...using raw sewage...to irrigate and fertilize”；文中“dangers are outweighed by the social and economic gains”对应选项C“benefits outweigh the hazards”。
解析：题干问作者对使用原污水进行农业种植的看法。答案句明确指出“it may not be a bad thing”，且“dangers are outweighed by the social and economic gains”，即收益大于风险，直接对应C选项“benefits outweigh the hazards”。A选项“risks cannot be overestimated”意为风险不能被高估，与原文相反；B选项“should be forbidden”无中生有；D选项“polluting”与原文“may not be a bad thing”态度不符。
47. What is the main problem caused by the use of wastewater for irrigation?
- A. Rivers and lakes nearby will gradually become contaminated.
- B. It will drive producers of chemical fertilizers out of business.
- C. Farmers and consumers may be affected by harmful bacteria.
- D. It will make the farm produce less competitive on the market.
答案：C
答案句：When this water is used for agricultural irrigation, farmers risk absorbing disease-causing bacteria, as do consumers who eat the produce raw and unwashed.
参考译文：当这些水用于农业灌溉时，农民有吸收致病细菌的风险，食用未清洗的生农产品的消费者也是如此。
定位线索：题干“main problem caused by the use of wastewater for irrigation”→答案句“When this water is used for agricultural irrigation, farmers risk absorbing disease-causing bacteria”；文中“farmers risk absorbing disease-causing bacteria”对应选项C“farmers and consumers may be affected by harmful bacteria”。
解析：题干问使用废水灌溉造成的主要问题。答案句直接指出农民和消费者面临吸收致病细菌的风险，即C选项“farmers and consumers may be affected by harmful bacteria”的同义转述。A选项“rivers and lakes contaminated”是原文提到的背景而非主要问题；B选项“drive producers of chemical fertilizers out of business”无中生有；D选项“less competitive”原文未提及。
50. What do we learn about James Bartram's position on the use of human waste for farming?
- A. He echoes Pay Drechsel's opinion on the issue.
- B. He challenges Liqa Raschid-Sally's conclusion
- C. He thinks it the only way out of the current food crisis.
- D. He deems it indispensable for combating global poverty.
答案：A
答案句：“Overly strict standards often fail,” James Bartram, a WHO water-health expert, said. “We need to accept that fact across much of the planet, so waste with little or no treatment will be used in agriculture for good reason.”
参考译文：“过于严格的标准往往行不通，”世界卫生组织水健康专家詹姆斯·巴特拉姆说。“我们需要接受这个事实，在世界上许多地方，未经处理或很少处理的废水将出于充分理由用于农业。”
定位线索：题干“James Bartram's position”→答案句“Overly strict standards often fail”和“waste with little or no treatment will be used in agriculture”；文中“accept that fact”对应选项A“echoes Pay Drechsel's opinion”（支持使用废水）。
解析：题干问James Bartram对使用人类排泄物进行农业的立场。答案句表明他认为严格标准行不通，应接受未经处理的废水用于农业，这与Pay Drechsel支持使用的观点一致，即A选项“echoes Pay Drechsel's opinion”。B选项“challenges Liqa Raschid-Sally's conclusion”错误，因为Liqa也提到“potential to help”；C选项“only way out”程度过重；D选项“indispensable for combating global poverty”范围扩大。