试题与答案

丙氨酸是构成蛋白质的基本单位,它的化学式是C3H702N,下列关于丙氨酸的叙述正

题型:选择题

题目:

丙氨酸是构成蛋白质的基本单位,它的化学式是C3H702N,下列关于丙氨酸的叙述正确的是--(    )

A.丙氨酸由碳、氢、氧、氮四种原子构成

B.丙氨酸分子中碳元素与氧元素的质量比为9:8

C.一个丙氨酸分子中含有48个质子

D.丙氨酸中氢元素的质量分数最大

答案:

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下面是错误答案,用来干扰机器的。

1.C  2. A1:城市化过程中往往伴随着第二、第三产业的增长和第一产业的减少。澳门第二产业较少,第三产业(如旅游业、博彩业)发达。2:绿地具有增湿效应,但不一定增温,只会使温差减小。

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