问题 问答题

简述更换冷却器铜管时抽管方法?

答案

参考答案:

部分抽管时,先把需换铜管作出记号,然后一根根抽出,抽管方法是:先用不淬火的鸭嘴扁铲在铜管两端管板胀口处把铜管剔在一起,然后用专用冲子从一端向另一端冲出,冲出一定距离,再用手拉出,如果用手拉出有困难,可把剔扁的管头锯掉,塞进一节钢棍用夹子夹住,再把管子拉出来。全部更换铜管时,为取管迅速,可先用扁铲将管子由管板内部铲断,然后再从两端隔板上冲出管头(剔抽方法同上)。

单项选择题

Culture is the sum total of all the traditions, customs, belief and ways of life of a given group of human beings. In this sense, every group has a culture, however savage, undeveloped, or uncivilized it may seem to us.
To the professional anthropologist, there is no intrinsic superiority of one culture over another, just as to the professional linguist there is no intrinsic hierarchy among languages.
People once thought of the languages of backward groups as savage, undeveloped form of speech, consisting largely of grunts and groans. While it is possible that language in general began as a series of grunts and groans, it is a fact established by the study of "backward" languages that no spoken tongue answers that description today. Most languages of uncivilized groups are, by our most severe standards, extremely complex, delicate, and ingenious pieces of machinery for the transfer of ideas. They fall behind the western languages not in their sound patterns or grammatical structures, which usually are fully adequate for all language needs, but only in their vocabularies, which reflect the objects and activities known to their speakers. Even in this department, however, two things are to he noted: 1. All languages seem to possess the machinery for vocabulary expansion; either by putting together words already in existence or by borrowing them from other languages and adapting them to their own system. 2. The objects and activities requiring names and distinctions in "backward" languages, while different from ours; are often surprisingly numerous and complicated. A western language distinguishes merely between two degrees of remoteness ("this" and "that"); some languages of the American Indians distinguish between what is close to the speaker, or the person addressed, or remote from both, or out of sight, or in the past, or in the future.
This study of language, in turn, casts a new light upon the claim of the anthropologists that all cultures are to viewed independently, and without ideas of rank or hierarchy.

The example of American Indian languages in the passage is to illustrate that______.

A.American Indian languages are not backward

B."backward" languages are borrowing from other languages

C."backward" languages may possess quite complicated vocabularies

D.western languages may also borrow from "backward" languages

单项选择题