问题 选择题

据报载,进入20世纪后,几乎每年至少有一种鸟类和哺乳动物从地球上消失。造成野生动物濒临灭绝的主要原因是(  )

A.栖息地的丧失

B.自然灾害

C.天敌过多

D.外来物种的入侵

答案

答案:A

题目分析:威胁生物生存的原因有栖息地被破坏、偷猎(滥捕乱杀)、外来物种入侵、环境污染、其他原因(自然灾害和动物疾病)等,生物多样性面临的威胁主要体现为物种灭绝的速度加快.生物多样性丧失的原因是多方面的.人口快速增长是破坏或改变野生动物栖息地和过度利用生物资源的最主要的原因,如乱砍滥伐、过度放牧、不合理开垦(围湖造田、垦荒、湿地开发等)、环境污染使环境不再适和生物生存等,使生物的栖息环境遭到破坏,使生物的生活环境越来越少,导致生物种类越来越少.因此野生动物栖息地的丧失是造成野生动物濒临灭绝的主要原因.

单项选择题
问答题

(46) Surprisingly enough, modern historians have rarely interested themselves in the history of the American South in the period before the South began to become self-consciously and distinctively "Southern"—the decades after 1815. Consequently, the cultural history of Britain’ s North American empire in the seventeenth and eighteenth centuries has been written almost as if the Southern colonies had never existed. The American culture that emerged during the Colonial and Revolutionary eras has been depicted as having been simply an extension of New England Puritan culture. However, Professor Davis has recently argued that the South stood apart from the rest of American society during this early period, following its own unique pattern of cultural development. (47) The case for Southern distinctiveness rests upon two related premises: first, that the cultural similarities among the five Southern colonies were far more impressive than the differences, and second, that what made those colonies alike also made them different from the other colonies. The first, for which Davis offers an enormous amount of evidence, can be accepted without major reservations; the second is far more problematic.

What makes the second premise problematic is the use of the Puritan colonies as a basis for comparison. Quite properly, Davis decries the excessive influence ascribed by historians to the Puritans in the formation of American culture. Yet Davis inadvertently adds weight to such ascriptions by using the Puritans as the standard against which to assess the achievements and contributions of Southern colonials. (48) Throughout, Davis focuses on the important, and undeniable, differences between the Southern and Northern colonies in motives for and patterns of early settlement, in attitudes toward nature and Native Americans, and in the degree of receptivity to metropolitan cultural influences.

(49) However, recent scholarship has ply suggested that those aspects of early New England culture that seem to have been most distinctly Puritan, such as the p religious orientation and the communal impulse, were not even typical of New England as a whole, but were largely confined to the two colonies of America. Thus, what in contrast to the Puritan (Northern) colonies appears to Davis to be peculiarly Southern—acquisitiveness, a p interest in politics and the law, and a tendency to cultivate metropolitan cultural models—was not only more typically English than the cultural patterns exhibited by Puritan Massachusetts and Connecticut, but also almost certainly characteristic of most other early modern British colonies from Barbados north to Rhode Island and New Hampshire. (50) Within the larger framework of American colonial life, then, not the Southern but the Northern colonies appear to have been distinctive, and even they seem to have been rapidly assimilating to the dominant cultural patterns by the last Colonial period.

(50) Within the larger framework of American colonial life, then, not the Southern but the Northern colonies appear to have been distinctive, and even they seem to have been rapidly assimilating to the dominant cultural patterns by the last Colonial period.