第三十二篇
The life story of the human species goes back a million years, and there is no doubt that man came only recently to the western hemisphere. None of the thousands of sites of aboriginal habitation uncovered in North and South America has antiquity comparable to that of old World sites. Mans occupation of the New World may date several tens of thousands of years, but no one rationally argues that he has been here even 100,000 years.
Speculation as to how man found his way to America was lively at the outset, and the proposed routes boxed the compass. With one or two notable exceptions, however, students of American anthropology soon settled for the plausible idea that the first immigrants came b way of a land bridge that had connected the northeast comer of Asia to the northwest corner of North America across the Bering Strait. Mariners were able to supply the reassuring information that the strait is not only narrow it is 56 miles wide but also shallow, a lowering of the sea level there by 100 feet or so would transform the strait into an isthmus . With little eels in the way of evidence to sustain the Bering Strait land bridge, anthropologists embraced the idea that man walked dryshod from Asia to America.
Toward the end of the last century, however, it became apparent that the Western Hemisphere was the New World not only for man but also for a host of animals and plants. Zoologists and botanists showed that numerous subjects of their respective kingdoms must have originated in Asia and spread to America. These findings were neither astonishing nor wholly unexpected. Such spread of populations is not to be envisioned as an exodus or mass migration, even in the case of animals. It is, rather, a spilling into new territory that accompanies increase in numbers, with movement in the direction of least population pressure and most favorable ecological conditions. But the immense traffic in plant and animals forms placed a heavy burden on the Bering Strait land bridge as the anthropologists ahead envisioned it. Whereas purposeful men could make their way across a narrow bridge, the slow diffusion of plant and animals would require an avenue as a continent and available for ages at a stretch.
1.The movement of plants and animals form Asia to America indicates ______.
A.that they could not have traveled across the Bering Strait
B.that Asia and the Western hemisphere were connected by a large land mass
C.that the Bering Sea was an isthmus at one time
D.that migration was in the one direction only
2.The author is refuting the notion that _____.
A.life arose in America independently of life in Europe
B.the first settlers in America came during the sixteenth century
C.a large continent once existed which has disappeared
D.man was a host to animals and plants
3.By using the words boxed the compass the author implies that _____.
A.the migration of mankind was from West to East
B.the migration of mankind was from East to West
C.mankind traveled in all directions
D.mankind walked from Asia to America
4.One reason for the migration not mentioned by the author is _____.
A.overcrowding
B.favorable environmental conditions
C.famine
D.the existence of a land bridge
5.We may assume that in the paragraph that follows this passage the author argues about______.
A.the contributions of anthropologist
B.the contributions of zoologists and botanists
C.the contributions made by the American Indians
D.the existence of a large land mass between Asia and North America
第32篇答案:BCCCD
英语四级语法:名词从句
每日一句:You don't have to do that,
简约主义生活
四级英语翻译:中秋习俗
初中英语语法:祈使句
英语四级语法must详解
小学生英语演讲稿
Live and Alive正确使用
Alone and Lonely辨析
面试英语自我介绍
每日一句:Sucess is the sum of small efforts
四级中英翻译:社交饥渴
反义疑问句详解
四级中英翻译:传统艺术
连词详解及练习
每日一句:Just one in five
每日一句:You only have to... in order to...
how与what习惯搭配及用法区别
每日一句:获得真正的幸福需要三件事情
Silence 安静
英语语句基本结构分析
英语四级语法总结:专有名词
定语从句专项练习
小学生英语演讲稿范文
高中英语美文赏析:Youth 青春
四级中英翻译:保护动物
英语四级语法:定语从句详解
助动词的用法详解
Three Days to See(假如给我三天光明)
四级中英翻译:介绍北京
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