大学英语自学教程 上册 un24

[08:31.60]在阿拉斯加，被称为北坡的广阔寒冷地带
[08:35.08]is part of the tundra.
[08:36.75]就是冻土带的一部分。
[08:38.43]Nature sets harsh terms for survival in thins land
[08:41.16]大自然为这片土地设置的生存条件十分严酷，
[08:43.89]only those plants and animals
[08:45.66]只有那些能适应恶劣环境的植物和动物
[08:47.44]that are adapted to the hostile environment can survive in it.
[08:50.38]才能在这里生存。
[08:53.32]Long periods of darkness and bitter cold
[08:55.59]长时间的黑暗和严寒
[08:57.86]are the major threats to life on the tundra.
[09:00.20]是这一地带生命的主要威胁。
[09:02.54]At the Arctic Circle,
[09:04.46]在北极圈，
[09:06.38]the sun cannot be seen above the horizon in December
[09:09.16]在12月，无法见到太阳升出地平线。
[09:11.94]North of the Circle, the darkness lasts even longer.
[09:14.62]极圈以北黑暗延续更长。
[09:17.30]Over the northern reaches of the tundra,
[09:19.63]冻土带的北部边缘以外，
[09:21.97]no sunlight can be seen at all for several months of the year?
[09:24.49]一年中甚至有好几个月根本见不到太阳。
[09:27.01]The darkness is balanced, to some degree
[09:29.20]在某种程度上说，
[09:31.38]by Continuous daylightduring the summer months.
[09:33.74]黑暗被连续不断的夏季白昼抵消了。
[09:36.10]But even in the warrmest month,
[09:37.84]但即使在最温暖的冬季月份，
[09:39.58]the temperature only averages about 50 degrees F (10 degrees C).
[09:43.16]气温的平均值才为大约50华氏度（10摄氏度）。
[09:46.74]During the dark winter months the average temperature falls to - 16 degrees
[09:50.42]在黑暗的冬季月份里，平均气温下降至零下16华氏度
[09:54.10](-27 degrees C),
[09:56.44]（零下27摄氏度），
[09:58.78]and sometimes to -40 degrees (C and F) and below.
[10:02.64]有时到零下40度（摄氏与华氏），甚至更低。
[10:06.51]Because of the intense cold,
[10:08.63]由于严寒，
[10:10.74]the subsoil of the tundraremains permanently frozen to a great depth.
[10:14.13]冻土带的下层土壤长久冻结很深。
[10:17.51]During the brief summer,
[10:19.43]在短暂的夏季，
[10:21.35]a few feet (about a meter) of soilthaw at the surface.
[10:24.52]几英尺（大约一米）厚的土地只是表层解冻，
[10:27.70]It is this thin layer of active soil
[10:29.81]就是这层薄薄的活土地支持着
[10:31.93]that supports all living things on the tundra.
[10:34.25]冻土带所有的生命。
[10:36.58]For nine months of the year,
[10:38.35]一年之中长达9个月，
[10:40.13]the tundra is a dark,seemingly lifeless wild land:
[10:42.95]冻土带一片黑暗，看上去像没有生命的荒野地。
[10:45.77]Then in Juhe,as if by magic,
[10:47.90]不过，到了6月份，
[10:50.03]a never-setting summet sun'
[10:51.91]如同变魔太一般，一个永不落山的夏季太阳
[10:53.79]gives birth to hurtdreds of speciesof arctic plants to cover the ground.
[10:56.91]给数百种北极植物以生命，使之覆盖大地。
[11:00.04]A plant that grows more than three feet
[11:02.36]长势超过3英尺
[11:04.69] (about a meter)is unusual on the tundra.
[11:07.10]（约1米）高的植物在冻土带十分罕见。
[11:09.52]There are no tall trees.
[11:11.24]没有高树，
[11:12.97]The frozen subsoil prevents rootsfrom growing deep enough to support them.
[11:16.00]冻结的下层土壤阻碍树根向足够的深层生长来供给高树营养。
[11:19.03]By the end of August the breath of winter returns
[11:21.67]到8月底，冬天的气息重返冻土带，
[11:24.30]and by mid-September the tundra is white again.
[11:26.88]到9月中旬冻土地又是白茫茫一片。
[11:29.45]The animal life on the tundra is unusually rich
[11:31.83]动物的生活在冻土带异乎寻常地丰富多彩。
[11:34.20]for an environment that seems so harsh.
[11:36.49]对于显得如此恶劣的环境来说，
[11:38.78] Herds of arctic deer move from place to place in search of food.
[11:41.81]成群的北极鹿为了寻找食物从一个地方迁徙至另一个地方，
[11:44.84]Bands of wolves follow them and hunt for the weak or sick ones.
[11:47.96]狼群尾随它们，猎食弱小的或者生病的鹿。
[11:51.08]Few birds actually live on the tundra.
[11:53.60]几乎没有鸟真正在活在冻土带。
[11:56.12]However, a variety of birds migrate to nest and feed during the summer.
[11:59.36]不过，各种不同的鸟在夏季迁徙到这里做巢捕食。
[12:02.60]The wet, marshy land produces a large number of insects
[12:05.38]潮湿的沼泽地产生大量昆虫