单选题关于脂肪酸β-氧化的叙述，错误的是

单选题下列关于酶化学修饰调节的叙述，错误的是

单选题下列关于物质在体内氧化和体外燃烧的特点，正确的是

单选题不属于高能磷酸化合物的是

单选题谷氨酸脱氨基作用的产物是

单选题关于转氨基作用的叙述，错误的是

单选题痛风症时，沉积于关节、肾等处的成分是

单选题有机磷农药中毒主要是它们能特异地和酶活性中心哪种基团结合

单选题下列能自由透过线粒体膜的物质是

单选题下列哪项属组成性基因表达

单选题In the two decades between 1910 and 1930, over ten percent of the Black population of the United States left the South, where the majority of the Black population had been located, and migrated to northern states, with the largest number moving, it is claimed, between 1016 and 1918. It has been frequently assumed, but not proved, that most of the migrants in what has come to be called the Great Migration came from rural areas and were motivated by two concurrent factors: the collapse of cotton industry following boll weevil infestation, which began in 1898, and increased demand in the North for labor following the cessation of European immigration caused by the outbreak of the First World War in 1914. This assumption has led to the conclusion that the migrants' subsequent lack of economic mobility in the North is tied to rural background, a background that implies unfamiliarity with urban living and a lack of industrial skills. But the question of who actually left the South has never been investigated in detail. Although numerous investigations document a flight from rural southern areas to southern cities prior to the Great Migration, no one has considered whether the same migrants then moved on to northern cities. In 1910 over 600,000 Black workers, or ten percent of the Black work force reported themselves to be engaged in "manufacturing and mechanical pursuits", the federal census category roughly including the entire industrial sector. The Great Migration could easily have been made up entirely of this group and their families. It is perhaps surprising to argue that an employed population could be tempted to move, but an explanation lies in the labor conditions then prevalent in the South. About thirty-five percent of the urban Black population in the South was engaged in skilled trades. Some were from the old artisan class of slavery--blacksmiths, masons, carpenters--which had a monopoly of certain trades, but they were gradually being pushed out by competition, mechanization, and obsolescence. The remaining sixty-five percent, more recently urbanized, worked in newly developed industries--tobacco, lumber, coal and iron manufacture, and railroads. Wages in the South, however, were low, and Black workers were aware, through labor recruiters and the Black press, that they could earn more even as unskilled workers in the North than they could as artisans in the South. After the boll weevil infestation, urban Black workers faced competition from the continuing influx of both Black and White rural workers, who Were driven to undercut the wages formerly paid for industrial jobs. Thus, a move north would be seen as advantageous to a group that was already urbanized and steadily employed, and the easy conclusion tying their subsequent economic problems in the North to their rural backgrounds comes into question. Notes: boll weevil infestation 棉铃虫蔓延。cessation 中止，停止。mason 泥瓦匠。recruiter 招募者。influx流入，涌入。

单选题关于蛋白质腐败作用的叙述，错误的是

单选题蛋白质-．螺旋的特性是（ ）

单选题下列哪个化合物脱下的2H不能通过NADH呼吸链传递产生能量

单选题血浆蛋白是组成血浆固体的主要成分，在临床上常利用盐析和电泳等方法将血浆蛋白大致分类。

单选题DNA依赖的RNA聚合酶的通读可以靠( )。

单选题将血浆蛋白置于pH8．6的缓冲液中进行醋酸纤维膜电泳时，泳动最慢的是

单选题尿素分子中的两个氨基，一个来自氨，另一个直接来自

单选题在适宜条件下，核酸分子两条链通过杂交作用可自行形成双螺旋，取决于______。

单选题关于糖原合成的叙述，错误的是