Life near the shore everywhere is affected by the tides, which come and go twice each day in a cycle of about twelve-and-a-half

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问题     Life near the shore everywhere is affected by the tides, which come and go twice each day in a cycle of about twelve-and-a-half hours—just different enough from the daily cycle of the sun so that there can be no regular relationship between the shore being alternately wet and dry and alternately light and dark. The extent of the tides varies greatly, from as little as one foot in inland seas like the Mediterranean, to fifty feet or so in the Bay of Fundy in Nova Scotia. In some parts of the world, one of the two daily tides rises higher and falls lower than the other; and tides at the time of new moon and full moon are generally greater than at other times. The extent of the intertidal zone thus varies from day to day as well as from place to place.
    The kinds of organisms living in the region between the tidal limits depend very much on whether the shore is rocky, sandy, or muddy. Rocky shores have the most obviously rich faunas (某地区所有的动物),because of the firm anchorage for both animals and plants, and because of the small pools left by the retreating seas. Sandy shores, especially when exposed to surf (as they usually are), have the fewest kinds of animals.
The composition of the intertidal soil affects______.

选项 A、the level of pollution in that area
B、the nature of tides
C、the temperature of the water in that area
D、the number of animals and plants living in that area

答案D

解析 文中第二段说:“在高潮线与低潮线之间地带生活的各种生物的生存在很大程度上依靠的是海岸是否由岩石、沙粒或泥土构成。岩岸很显然有最丰富的生物群,因为对于动物和植物来说,那里有坚固的泊地和退潮后留下的小水坑。而沙岸,特别是受海浪侵袭时(它们通常都是这样),却只有最少类别的生物存在。”由此可知,潮间带土壤的成分影响着该地区动物和植物的数量。
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