试题与答案

酚类主要来自工业排废,又是染料、制药、树脂含成等工业的重要原料。动、植物代谢及机体分

题型:单项选择题 共用题干题

题目:

酚类主要来自工业排废,又是染料、制药、树脂含成等工业的重要原料。动、植物代谢及机体分解也有酚类物质生成,故酚类物质与人类关系极其密切。酚类物质虽毒性不高,但多有恶臭,是卫生检验的重要项目

质分析中,如何制备挥发酚类样品?()

A.取一定量水样,酸化后,乙醚萃取,脱水,然后浓缩至一定体积

B.取1~2升水样,过大孔树脂XAD-4柱,而后经有机溶剂洗脱,定容

C.取水样,硫酸酸化,经水蒸气蒸馏使馏出液达原取样体积近蒸馏尾声可适量向残液补水

答案:

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题型:单项选择题

For a trade embargo against a particular country to succeed, a high degree of both international accord and ability to prevent goods from entering or leaving that country must be sustained. A total blockade of Petrie’s ports is necessary to an embargo, but such an action would be likely to cause international discord over the embargo.
The claims above, if true, most ply support which of the following conclusions

A.The balance of opinion is likely to favor Petrie in the event of a blockade.

B.As long as international opinion is unanimously against Petrie, a trade embargo is likely to succeed.

C.A naval blockade of Patria’s ports would ensure that no goods enter or leave Patria.

D.Any trade embargo against Petrie would be likely to fail at some time.

E.(E) For a blockade of Patria’s ports to be successful, international opinion must be unanimous.

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