To understand the ancient Mayan people who lived in the area that is today southern Mexico and Central America and the ecological difficulties they faced, one must first consider their environment, which we think of as “jungle” or “tropical rainforest.” This view is inaccurate, and the reason proves to be important. Properly speaking, tropical rainforests grow in high-rainfall equatorial areas that remain wet or humid all year round. But the Maya homeland lies more than sixteen hundred kilometers from the equator, at latitudes 17 to 22 degrees north, in a habitat termed a “seasonal tropical forest.” That is, while there does tend to be a rainy season from May to October, there is also a dry season from January through April. If one focuses on the wet months, one calls the Maya homeland a “seasonal tropical forest”; if one focuses on the dry months, one could instead describe it as a “seasonal desert.”
From north to south in the Yucatan Peninsula, where the Maya lived, rainfall ranges from 18 to 100 inches (457 to 2,540 millimeters) per year, and the soils become thicker, so that the southern peninsula was agriculturally more productive and supported denser populations. But rainfall in the Maya homeland is unpredictably variable between years; some recent years have had three or four times more rain than other years. As a result, modern farmers attempting to grow corn in the ancient Maya homelands have faced frequent crop failures, especially in the north. The ancient Maya were presumably more experienced and did better, but nevertheless they too must have faced risks of crop failures from droughts and hurricanes.
Although southern Maya areas received more rainfall than northern areas, problems of water were paradoxically more severe in the wet south. While that made things hard for ancient Maya living in the south, it has also made things hard for modern archaeologists who have difficulty understanding why ancient droughts caused bigger problems in the wet south than in the dry north. The likely explanation is that an area of underground freshwater underlies the Yucatan Peninsula, but surface elevation increases from north to south, so that as one moves south the land surface lies increasingly higher above the water table. In the northern peninsula the elevation is sufficiently low that the ancient Maya were able to reach the water table at deep sinkholes called cenotes, or at deep caves. In low-elevation north coastal areas without sinkholes, the Maya would have been able to get down to the water table by digging wells up to 75 feet (22 meters) deep. But much of the south lies too high above the water table for cenotes or wells to reach down to it. Making matters worse, most of the Yucatan Peninsula consists of karst, a porous sponge-like limestone terrain where rain runs straight into the ground and where little or no surface water remains available.
How did those dense southern Maya populations deal with the resulting water problem? It initially surprises us that many of their cities were not built next to the rivers but instead on high terrain in rolling uplands. The explanation is that the Maya excavated depressions, or modified natural depressions, and then plugged up leaks in the karst by plastering the bottoms of the depressions in order to create reservoirs, which collected rain from large plastered catchment basins and stored it for use in the dry season. For example, reservoirs at the Maya city of Tikal held enough water to meet the drinking water needs of about 10,000 people for a period of 18 months. At the city of Coba the Maya built dikes around a lake in order to raise its level and make their water supply more reliable. But the inhabitants of Tikal and other cities dependent on reservoirs for drinking water would still have been in deep trouble if 18 months passed without rain in a prolonged drought. A shorter drought in which they exhausted their stored food supplies might already have gotten them in deep trouble, because growing crops required rain rather than reservoirs.
58. Why does the author call the Mayan homeland both a “seasonal tropical forest” and “seasonal desert”?
59. Which of the following statements about ancient and modern agriculture in the Yucatan Peninsula is supported by paragraph 2?
60. Which of the following statements about the availability of water in the Mayan homeland is supported by paragraph 3?
61. According to the passage, why was the southern Mayan homeland hard to farm?
问题1选项
A.To illustrate how the climate of the Mayan homeland varied from region to region.
B.To explain how the climate of the Mayan homeland is similar to that of a jungle or tropical rainforest.
C.To emphasize the vast size of the area that compromised the Mayan homeland in ancient times.
D.To make the point that the Mayan homeland is climatically more complex than is generally assumed.
问题2选项
A.Modern agricultural methods have solved many of the ancient problems of farming in the Yucatan Peninsula.
B.Ancient Mayan farmers may have been somewhat more successful at farming in the Yucatan Peninsula than farmers are today.
C.Farming today is easier than in the past because environmental changes in the Yucatan Peninsula have increased available rainfall.
D.The Yucatan soils in which ancient farmers worked were richer, more productive, and thicker than they are today.
问题3选项
A.The construction of wells was an uncommon practice in both the north and the south because it was too difficult to dig through the karst.
B.In most areas in the north and the south, rainwater was absorbed directly into the porous karst.
C.The water table was an important resource for agriculture in both the north and the south of the Yucatan Peninsula.
D.The lack of surface water in both the north and the south was probably due to the fact that most of it was quickly used up for agricultural purposes.
问题4选项
A.The presence of numerous sinkholes and wells interfered with farming.
B.Southern soil lacked the depth crops needed for growth.
C.Underground water was too far below the surface to reach.
D.The presence of karst caused frequent flooding.
58.【试题答案】D
【试题解析】推理判断题。题干意思是“为什么作者称玛雅家园为‘季节性热带雨林’和‘季节性的沙漠’?”。根据第一段中的Properly speaking, tropical rainforests grow in high-rainfall equatorial areas that remain wet or humid all year round. But the Maya homeland lies more than sixteen hundred kilometers from the equator, at latitudes 17 to 22 degrees north, in a habitat termed a “seasonal tropical forest.” That is, while there does tend to be a rainy season from May to October, there is also a dry season from January through April.(确切地说,热带雨林生长在赤道多雨地区,终年潮湿。但是玛雅的家园位于北纬17到22度,距离赤道1600多公里,在一个被称为“季节性热带森林”的栖息地。也就是说,虽然5月到10月确实有雨季,但1月到4月也有旱季。)可知,玛雅家园的气候比一般的要复杂,D项“为了表明玛雅家园的气候比一般认为的要复杂”正确。A项“以说明玛雅家园的气候如何因地区而异”,文中并没有说各个地区不同;B项“来解释玛雅人家园的气候与丛林或热带雨林的相似之处”只说到了雨季,没有说旱季;C项“为了强调古代玛雅家园的广阔面积”中的“广阔面积”在文中也没有提及。因此,该题选择D项正确。
59.【试题答案】B
【试题解析】细节推理题。题干意思是“关于尤卡坦半岛古代和现代农业,下列哪一项陈述得到第2段的支持?”。根据关键词ancient和modern定位到第二段最后两句As a result, modern farmers attempting to grow corn in the ancient Maya homelands have faced frequent crop failures, especially in the north. The ancient Maya were presumably more experienced and did better, but nevertheless they too must have faced risks of crop failures from droughts and hurricanes.(因此,现代农民要在玛雅遗址种植谷物就要面临频繁的作物减产的风险,尤其在半岛的北部地区。古玛雅人也许更有经验也做得更好,但是不管怎么说他们都必须面对旱灾和飓风带来的颗粒无收的风险。),由此可知,现代和古代的玛雅人都会遇到同样的问题,即自然灾害带来的作物减产,但在某种程度上,古代人比现代人解决的更好,因此B项“古代玛雅农民在尤卡坦半岛的农业可能比今天的农民更成功”符合题意,A项“现代农业方法解决了尤卡坦半岛许多古老的农业问题”正好相反,A项错误。C项“由于尤卡坦半岛的环境变化增加了可用的降雨量,今天的农业比过去更容易”和D项“古代农民耕种的尤卡坦半岛的土壤比现在更肥沃、更多产、更厚”在该段都没提到。因此,该题选择B项正确。
60.【试题答案】B
【试题解析】细节事实题。题干意思是“以下哪一项关于玛雅家园水资源的陈述得到了第3段的支持?”。根据第三段倒数第二句和第三句In low-elevation north coastal areas without sinkholes, the Maya would have been able to get down to the water table by digging wells up to 75 feet (22 meters) deep. But much of the south lies too high above the water table for cenotes or wells to reach down to it.(在没有排水口且海拔较低的北部沿海地区,玛雅人就需要借助凿井到达75英尺深的地下水含水层。但在南方若想通过排水口或凿井达到含水层的话,深度就要深得多。)可知,北部打井容易而南部却很难,所以A项“无论是在北方还是南方,打井都是一种罕见的做法,因为在岩溶中挖掘太困难了”错误,C项“地下水位是尤卡坦半岛北部和南部重要的农业资源”中的“地下水位”虽然有提及,但是并没有提到它的重要性,所以C项也不选。由第三段最后一句Making matters worse, most of the Yucatan Peninsula consists of karst, a porous sponge-like limestone terrain where rain runs straight into the ground and where little or no surface water remains available.(更糟糕的是,尤卡坦半岛大部分地区属于喀斯特地貌,多孔状如海绵的石灰岩地形,雨水直接流入地下,几乎没有地表水余留。)可知,B项“在北方和南方的大部分地区,雨水被直接吸收到多孔的喀斯特地貌”符合原文。D项“北方和南方地表水的缺乏可能是由于大部分地表水很快被用于农业用途”在原文中没有对应。因此,该题选择B项正确。
61.【试题答案】C
【试题解析】推理判断题。题干意思是“根据文章,为什么南部玛雅人的家园很难耕种?”。根据第三段第三句The likely explanation is that an area of underground freshwater underlies the Yucatan Peninsula, but surface elevation increases from north to south, so that as one moves south the land surface lies increasingly higher above the water table.(可能的解释是,尤卡坦半岛的地下有一片淡水区域,但地表高度从北向南增加,所以当你向南移动时,地表高于地下水位的位置越来越高。)可推知,玛雅南部的地表高于地下水位,所以地下水无法达到地表,从而南部玛雅人很难耕种,故C项“地下水在地表以下很远,无法到达”正确。根据第三段倒数第二句But much of the south lies too high above the water table for cenotes or wells to reach down to it.(但在南方若想通过排水口或凿井达到含水层的话,深度就要深得多。)可知,在玛雅南部凿井是很困难的,所以A项“大量排水口和井的存在妨碍了农业”是错误的。B项“南方土壤缺乏作物生长所需的深度”在原文中没有提到。由第三段最后一句Making matters worse, most of the Yucatan Peninsula consists of karst, a porous sponge-like limestone terrain where rain runs straight into the ground and where little or no surface water remains available.(更糟糕的是,尤卡坦半岛大部分地区属于喀斯特地貌,多孔状如海绵的石灰岩地形,雨水直接流入地下,几乎没有地表水余留。)可知,喀斯特地貌导致的是雨水直接流下地下,而不是洪水,D项“喀斯特地貌的存在导致频繁的洪水”错误。因此,该题选择C项正确。