某物质能吸收红外光波,产生红外吸收谱图,其分子结构必然是()。 A.发生偶极矩的净变

题型:单项选择题

问题:

某物质能吸收红外光波,产生红外吸收谱图,其分子结构必然是()。

A.发生偶极矩的净变化

B.具有不饱和键

C.具有对称性

D.具有共轭体系

考点:生化化工药品技能考试仪器分析工(中级)仪器分析工(中级)题库
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周围性肺痛最常见的组织学类型是

A.腺癌

B.肺泡细胞癌

C.未分化癌

D.鳞状上皮细胞癌

E.转移癌

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Every group has a culture, however 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 undeveloped. 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. They differ from 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 aspect, two things are to be noted. First, 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. Second, the objects and activities requiring names and distinctions in "backward" languages, while different from the West, are often surprisingly numerous and complicated. A Western language distinguishes merely between two degrees of remoteness ("this" and "that"). But some languages of the American Indians distinguish between what is close to the speaker, or to the person addressed, or removed from both, or out of sight, or in the past, or in the future.

This passage is on the whole______.

A.narrative

B.instructive

C.prescriptive

D.argumentative

题型:单项选择题

被俄罗斯人誉为“母亲河”的是()

A.鄂毕河

B.多瑙河

C.伏尔加河

D.莱茵河

题型:单项选择题

联合国五大常任理事国是那几个国家?

题型:单项选择题

使用氢火焰离子化检测器的色谱仪要去除()中的含碳有机物。

A、载气

B、助燃气

C、燃气

D、以上全包括

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