正确答案: B

辅酶Ⅱ

题目：下列辅酶或辅基中含有维生素PP的是

解析：B

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举一反三的答案和解析：

[单选题]菲利普斯曲线描述（ ）之间有关系。

失业与通货膨胀 B． 失业与产量

[单选题]根据下列文章，回答36～40题。In 1784, five years before he became president of the United States, George Washington, 52, was nearly toothless. So he hired a dentist to transplant nine teeth into his jaw - having extracted them from the mouths of his slaves.That's a far different image from the cherry-tree-chopping George most people remember from their history books. But recently, many historians have begun to focus on the roles slavery played in the lives of the founding generation. They have been spurred in part by DNA evidence made available in 1998, which almost certainly proved Thomas Jefferson had fathered at least one child with his slave Sally Hemings. And only over the past 30 years have scholars examined history from the bottom up. Works of several historians reveal the moral compromises made by the nation's early leaders and the fragile nature of the country's infancy. More significantly, they argue that many of the Founding Fathers knew slavery was wrong - and yet most did little to fight it.

stress the role of slaves in the U.S. history.

解析：根据文章的逻辑一致性和联系，从第二段的“But recently, many historians have begun to focus on the roles of slavery…..”可以看出作者在第一段举George Washing(第一任美国总统)对待奴隶的例子是为了说明“美国历史上奴隶制的作用”。因此选C。

[单选题]The growth of specialisation in the 19th century might be more clearly seen in scien -ces such as _______ .

physics and chemistry

解析：选［D］。本题属细节类题目。文章第二段最后一句为正确解答本题提供了帮助。这一句中的关键词是"in those areas of science based especially on a mathe matical or laboratory training"这就表明了专业分工较为明显的学科的性质，即一般都是建立在数学或实验室研究方面的学科。所给四个选项中只有［D］物理学和化学是正确选项。

[单选题]党的十七届四中全会指出，保持马克思主义执政党先进性和纯洁性的根本要求和重要保证是

把干部的德放在首要位置． B．把干部的才放在首要位置

[单选题]原核生物中具有GTP酶活性的翻译起始因子是

IF2

[多选题]我国社会主义初级阶段的公有制经济形式有

国有经济

集体经济

混合所有制经济中的国有成分和集体成分

解析：ABD