The wet rice fields of Asia are the most productive of all preindustrial intensive agricultural systems. As the term “wet rice” suggests, the method involves flooding the fields for most of the growing season. In some areas the water comes entirely from the natural rainfall of the monsoons, but the water level often is controlled by artificial irrigation. Most wet rice is, therefore, grown on the floodplains of rivers. In parts of Southeast Asia, southern China, and the Himalayan fringes, wet rice is grown on terraced hillsides originally constructed centuries ago.

Perhaps the most remarkable feature of wet rice cultivation is the capability of a plot to yield a harvest year in the year out, with little or no need to be left uncultivated for extended periods in order to recover its fertility. Indeed, where the seasonal availability of water is adequate, the same plot may yield two and even three harvests in a single year, being under almost continuous cultivation. This capability has been attributed to four factors: the protection from erosion the water gives the soil, the high water table of the rivers’ floodplains that reduces the leaching of nutrients from the soil, the replacement of soil nutrients by the silt carried in the rivers’ flooding, and nitrogen fixation (the conversion of atmospheric nitrogen into forms usable by plants) from the blue-green algae that live in the floodwater. The chief benefit of wet rice--- its ability to grow in the same field year after year --- is then related to the practice of flooding the fields and allowing the water to remain throughout most of the maturation period.

Despite the advantages of their methods, wet rice farmers must solve problems relating to the management of water, because the proper supply of water at the proper time is some important for a good yield. It is more efficient if storage ponds or tanks, canals, ditches, and other improvements are held and managed communally, because less labor is required to construct and maintain them than if each family owned its own. Water may be stored in small lakes or ponds or captured and held in tanks until it is used to flood the fields. The water level must be controlled fairly precisely white the rice is growing: if it rises too high, the plants will be unable to photosynthesize; and if it falls too low, the benefits of having standing water in the fields will be reduced. Unless the land is naturally flat, the plots, therefore, must be leveled to keep the height of the water constant in different ares of the field. The water level must be controlled by low dikes, usually constructed of earth, which can be easily breached to drain the plot for the harvest.

Managing the supply of the water that is so critical in growing wet rice requires sophisticated organization, especially with respect to cooperative labor patterns and rights of access to both land and water. Each family may work its lands on its own, but who will construct and maintain public irrigation works? Who will decide when dikes, dams ditches, and tanks need to be repaired, and how will the labor to repair them be coordinated? The water used on the fields of one family is not available to other families. How shall the consumption of water be coordinated? Who will get how much water and when? How, in short, will use rights to water be determined?

In one example of organizing the allocation of water to the fields, the Sinhalese of the dry zone of Sri Lanka draw water from a collectively owned rain-fed reservoir constructed of earth. All of the cultivated land of a village is in a single area, below the reservoir. The entire field is laid out into diked plots of equal size. Each plot receives a fixed amount of water from the communal reservoir, though the number of families working a single plot varies: Poor families must share water rights of access to one plot with other families, whereas richer families have access to several plots. Assigning each plot (rather than each family) the same proportion of irrigation water reduces the chance that a given plot will receive insufficient moisture.

Questions:
question_stem: Paragraph 1 suggests which of the following about the artificial irrigation of wet rice?
choices: tag: A
text: It is used only in areas where there is little natural rainfall.

tag: B
text: It is most easily accomplished when the rice fields are located on the floodplains or rivers.

tag: C
text: It is considered one of the most important developments of industrial agriculture.

tag: D
text: It was not yet in use when the terraced hillsides were originally constructed.
answer_key: B
explanation: suggest 为“暗示”，此题为推断题。段落1暗示关于水稻的人工灌溉的哪个观点？
解析：段落1提到水稻的人工灌溉通常用于洪泛平原，这意味着在河流洪泛平原上更容易实施人工灌溉。因此答案：B. 它在水稻田地位于河流洪泛平原时最容易实施

question_stem: The phrase “ attributed to” in the passage is closest in meaning to
choices: tag: A
text: divided into

tag: B
text: reduced

tag: C
text: explained by

tag: D
text: proven by
answer_key: C
explanation: 文中短语""attributed to""在段落中的含义与以下哪个最接近？
A. 分为 B. 减少 C. 解释为 D. 由...证明
在段落2中，""attributed to""表示对水稻栽培能连年产出丰收的原因进行解释。因此，选 C

question_stem: According to paragraph 2, the flooding of wet rice fields is responsible for each of the following benefits EXCEPT
choices: tag: A
text: reduced erosion

tag: B
text: harvests that increase yearly in amount

tag: C
text: the regular addition of nutrients to the soil

tag: D
text: nitrogen fixation
answer_key: B
explanation: 根据段落2，以下哪项不是涝田水稻的洪水灌溉带来的好处？
段落2提到了水稻洪水灌溉的好处，包括 A 减少侵蚀对应原文 the protection from erosion the water gives the soil；C 养分补充对应 that reduces the leaching of nutrients from the soil；D 固氮，对应 and nitrogen fixation (the conversion of atmospheric nitrogen into forms usable by plants) from the blue-green algae that live in the floodwater.但没有提到年度收成逐年增加。因此答案：B. 年度收成逐年增加

question_stem: What is the role of the last sentence of paragraph 2?
choices: tag: A
text: To apply the ideas of the paragraph to a new case

tag: B
text: To summarize the ideas of the paragraph

tag: C
text: To emphasize a surprising consequence of the ideas of the paragraph

tag: D
text: To explain why the ideas of the paragraph are important
answer_key: B
explanation: 段落2的最后一句的作用是什么？
A. 将段落中的思想应用到一个新情况
B. 总结段落的思想
C. 强调段落思想的一个令人吃惊的结果
D. 解释为什么段落的思想很重要
解析：段落2的最后一句解释了为什么洪水灌溉对水稻栽培的连年生产力至关重要。

question_stem: The word “captured” in the passage is closest in meaning to
choices: tag: A
text: trapped

tag: B
text: transported

tag: C
text: shared

tag: D
text: cleaned
answer_key: A
explanation: 文中的“captured”一词在段落中的含义最接近以下哪个？A 被困住 B 运输   C 分享，共有    D 清理。
在段落中，captured 和 held 并列，指的是被捕获。因此选 A。

question_stem: According to paragraph 3, uneven land must be leveled before its is suitable for wet rice growing because
choices: tag: A
text: less water is needed to flood every part of a field when the field is level

tag: B
text: the height of water in which rice plants are growing must be kept constant

tag: C
text: the water levels in the fields must be reduce for the harvest

tag: D
text: draining the plots for the harvest is faster when the land is leveled
answer_key: B
explanation: 根据段落3，为什么不平坦的土地在适合种植水稻之前必须进行平整？
解析：不平坦的土地需要被平整，以确保水位在不同地区的水稻植株生长期间保持恒定，以便植物正常生长。Unless the land is naturally flat, the plots, therefore, must be leveled to keep the height of the water constant in different areas of the field.因此答案：B. 水稻植株生长时的水位必须保持恒定。

question_stem: According to paragraphs 4, in wet rice areas all of the following are problems that require cooperation to solve EXCEPT
choices: tag: A
text: deciding how available water should be distributed among its different users.

tag: B
text: organizing labor to repair water storage facilities

tag: C
text: arranging for the construction of irrigation works

tag: D
text: ensuring that enough workers are available to cultivate each plot
answer_key: D
explanation: 根据第4段，在水稻种植区，以下哪项不是需要合作解决的问题？
A. 决定如何分配可用水资源给不同的用户，对应 The water used on the fields of one family is not available to other families.
B. 组织劳动力来修复水库和水库，对应 Who will decide when dikes, dams, ditches, and tanks need to be repaired, and how will the labor to repair them be coordinated?
C. 安排灌溉工程的建设，对应 but who will construct and maintain public irrigation works
D. 确保有足够的工人来耕种每块土地
段落4提到了需要合作解决的问题，包括修建和维护公共灌溉工程、分配可用水资源以及协调劳动力来修复水源设施等问题。然而，没有提到需要合作解决足够的工人来耕种每块土地这个问题，因此 D

question_stem: Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information
choices: tag: A
text: Poor families who must share a plot have access to less water from the communal reservoir than do rich families who have their own plots.

tag: B
text: Each plot receives the same amount of water from the communal reservoir regardless of the number of families who work that plot, which varies depending on the wealth.

tag: C
text: Because each plot receives the same amount of water from the communal reservoir, poor families have access to just as much water for their plots as wealthy families do.

tag: D
text: The amount of water each plot receives from the communal reservoir is fixed according to the wealth of the families who have access to that plot
answer_key: B
explanation: 原句为转折让步逻辑。每个地块被分配的水量是固定的，尽管在一块地上工作的家庭数是变化的：……后面就是解释家庭数量的变化—穷家庭如何如何然而富裕家庭又如何如何，这个部分是次要信息。看选项：
A 选项句子主干表达的是贫穷家庭获水少，错，文章说每个地块获水一样，不是安穷富划分的；
B 选项主干说的就是每个地块获水量一样，不管在这里有多少家庭工作；正确
C 选项因果关系错误，虚假逻辑；D 选项说的是获水量是按照财富划分的错