问题 选择题

下列做法中符合安全用电原则的是(  )

A.用湿手插电源插头

B.有金属外壳的用电器的电源插头采用三脚插头

C.人体不能接触高压带电体,但可以靠近高压带电体

D.许多大功率用电器的电源插头插在同一插线板上同时工作

答案

A、湿手插插头容易触电,不安全;

B、正确使用三脚插头,可使用电器外壳接地,当漏电时,电流从地线直接流入大地,不经过人体,使人不会触电,符合安全用电原则;

C、人靠近高压带电体会发生触电;

D、这是家庭电路电流过大的原因之一,总功率过大.

故选B.

单项选择题
单项选择题

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. 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 recitations, 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. Throughout, Davis focuses on the important and undeniable differences between the Southern and Puritan 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.

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 Massachusetts and Connecticut. Thus, what in contrast to the Puritan colonies appears to Davis to be peculiarly Southern-acquisitiveness. A p interest in polities and the law, and a tendency to cultivate metropolitan cultural models were 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. Within the larger framework of American colonial life, then, not the Southern but the Puritan 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.

The word "premises" (Pard. 2) most probably means()

A. presupposition

B. prestigious

C. prevalent

D. prejudice