Passage Two
Questions 51 to 55 are based on the following passage.
Organic agriculture is a relatively untapped resource for feeding the Earth's population, especially in the face of climate change and other global challenges. That's the conclusion I reached in reviewing 40 years of science comparing the long-term prospects of organic and conventional farming.
The review study, “Organic Agriculture in the 21st Century,” is featured as the cover story for the February issue of the journal Nature Plants. It is the first to compare organic and conventional agriculture across the main goals of sustainability identified by the National Academy of Sciences: productivity, economics, and environment.
Critics have long argued that organic agriculture is inefficient, requiring more land to yield the same amount of food. It's true that organic farming produces lower yields, averaging 10 to 20 percent less than conventional. Advocates contend that the environmental advantages of organic agriculture far outweigh the lower yields, and that increasing research and breeding resources for organic systems would reduce the yield gap. Sometimes excluded from these arguments is the fact that we already produce enough food to more than feed the world's 7.4 billion people but do not provide adequate access to all individuals.
In some cases, organic yields can be higher than conventional. For example, in severe drought conditions, which are expected to increase with climate change in many areas, organic farms can produce as good, if not better, yields because of the higher water-holding capacity of organically farmed soils.
What science does tell us is that mainstream conventional farming systems have provided growing supplies of food and other products but often at the expense of other sustainability goals.
Conventional agriculture may produce more food, but it often comes at a cost to the environment. Biodiversity loss, environmental degradation, and severe impacts on ecosystem services have not only accompanied conventional farming systems but have often extended well beyond their field boundaries. With organic agriculture, environmental costs tend to be lower and the benefits greater.
Overall, organic farms tend to store more soil carbon, have better soil quality, and reduce soil erosion compared to their conventional counterparts. Organic agriculture also creates less soil and water pollution and lower greenhouse gas emissions. And it’s more energy-efficient because it doesn't rely on synthetic fertilizers or pesticides.
Organic agriculture is also associated with greater biodiversity of plants, animals, insects and microorganisms as well as genetic diversity. Biodiversity increases the services that nature provides and improves the ability of farming systems to adapt to changing conditions.
Despite lower yields, organic agriculture is more profitable for farmers because consumers are willing to pay more. Higher prices, called price premiums, can be justified as a way to compensate farmers for providing ecosystem services and avoiding environmental damage or external costs.
51. What do we learn from the conclusion of the author's review study?
A) More resources should be tapped for feeding the world's population.
B) Organic farming may be exploited to solve the global food problem.
C) The long-term prospects of organic farming are yet to be explored.
D) Organic farming is at least as promising as conventional farming.
52. What is the critics' argument against organic farming?
A) It cannot meet the need for food.
B) It cannot increase farm yields.
C) It is not really practical.
D) It is not that productive.
53. What does the author think should be taken into account in arguing about organic farming?
A) growth in world population.
B) Deterioration in soil fertility.
C) Inequality in food distribution.
D) advance in farming technology.
54. What does science tell us about conventional farming?
A) It will not be able to meet global food demand.
B) It is not conducive to sustainable development.
C) It will eventually give away to organic farming.
D) It is going mainstream throughout the world.
55. Why does the author think higher prices of organic farm produce are justifiable?
A) They give farmers going organic a big competitive edge.
B) They motivate farmers to upgrade farming technology.
C) Organic farming costs more than conventional farming.
D) Organic farming does long-term good to the ecosystem.
答案解析：
由题干中的关键词“conclusion of the author's review study”定位到第一段“Organic agriculture is a relatively untapped resource for feeding the Earth's population, especially in the face of climate change and other global challenges.”，这里提到有机农业是养活地球人口的相对未开发资源，尤其面对气候变化等全球挑战时，意味着有机农业可被开发来解决全球粮食问题，所以选B。
由题干中的关键词“critics' argument against organic farming”定位到第三段“Critics have long argued that organic agriculture is inefficient, requiring more land to yield the same amount of food. It's true that organic farming produces lower yields...”，批评者认为有机农业效率低，产量比传统农业低10%到20%，即有机农业生产力不高，所以选D。
由题干中的关键词“arguing about organic farming”定位到第三段“Sometimes excluded from these arguments is the fact that we already produce enough food to more than feed the world's 7.4 billion people but do not provide adequate access to all individuals.”，作者认为在讨论有机农业时，应考虑到我们已经生产了足够养活74亿人的食物，但却不能让所有人都能获得，即食物分配不均的问题，所以选C。
由题干中的关键词“science tell us about conventional farming”定位到第五段“What science does tell us is that mainstream conventional farming systems have provided growing supplies of food and other products but often at the expense of other sustainability goals.”和第六段“Conventional agriculture may produce more food, but it often comes at a cost to the environment.”，科学表明传统农业虽提供更多食物，但往往以牺牲其他可持续发展目标为代价，对环境有损害，即不利于可持续发展，所以选B。
由题干中的关键词“higher prices of organic farm produce are justifiable”定位到最后一段“Higher prices, called price premiums, can be justified as a way to compensate farmers for providing ecosystem services and avoiding environmental damage or external costs.”，作者认为有机农产品价格更高是合理的，因为这是对农民提供生态系统服务、避免环境破坏或外部成本的补偿，即有机农业对生态系统有长期好处，所以选D。
