TPO 问题

alicejingli

TPO14  第二篇

Although southern Maya areas received more rainfall than northern areas, problems of water were paradoxicallymore 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 the 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, 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 well to karst, a porous sponge-like limestone terrain where rain straight into the ground and where little or no surface water remains available.
我想问这个第六题为啥选B，从哪定位的？谢谢
6. Which of the following statements about the availability of water in the Mayan homeland is supported by paragraph 3?
? 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.
? In most areas in the north and the south, rainwater was absorbed directly into the porous karst.
? The water table was an important resource for agriculture in both the north and the south of the Yucatan Peninsula.
? 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.