单选题DNA分子的腺嘌呤含量为20%，则胞嘧啶的含量应为

单选题A．氢化物B．抗酶素AC．寡酶素D．二硝基苯酚E．异戊巴比妥

单选题可不使蛋白质变性的是

单选题下列哪种辅酶中不含维生素

单选题下列哪种物质不是嘌呤核苷酸从头合成的直接原料

单选题下列关于DNA转录的叙述正确的是

单选题氨基酸在肝、肾中将氨基转移给

单选题翻译后高级结构的加工修饰不包括

单选题下列关于RNA功能的叙述，错误的是

单选题磷脂分子最重要的特征是

单选题脂肪动员时脂肪酸在血液中的运输形式是

单选题合成尿素的主要器官是

单选题Ⅳ型高脂血症的血脂变化为

单选题Should anyone much care whether an American boy living overseas gets six vicious thwacks on his backside? So much has been argued, rejoined and rehashed about the case of Michael Fay, an 18-year-old convicted of vandalism and sentenced to a caning in Singapore, that an otherwise sorry little episode has shaded into a certified International Incident, complete with intercessions by the U. S. head of state. An affair has outraged American libertarians even as it has animated a general debate about morality East and West and the proper functioning of U.S. law and order. Which, to all appearances, is what Singapore wanted. The question of whether anyone should care about Michael Fay is idle. though Singapore officials profess shock at the attention his case had drawn, they know Americans care deeply about the many sides of this issue. Does a teenager convicted of spraying cars with easily removable paint deserve half a dozen powerful strokes? At what point does swift, sure punishment become torture? By what moral authority can America, with its high rates of lawlessness and license, preach of a safe society about human rights? The caning sentence has concentrated minds wondrously on an already lively domestic debate over what constitutes a due balance between individual and majority rights. Too bad Michael Fay has become a focus for this discussion. Not only does he seem destined to be pummeled and immobilized, but the use of Singapore as a standard for judging any other society, let alone the cacophonous U. S. , is fairly worthless. To begin with, Singapore is an offshore republic that tightly limits immigration. Imagine crime-ridden Los Angeles, to which Singapore is sometimes contrasted, with hardly any inflow of the hard-luck, often desperate fortune seekers who flock to big cities. Even without its government's disciplinary measures, Singapore more than plausibly would be much the same as it is now. An academic commonplace today is that the major factor determining social peace and prosperity is culture--a sense of common identity, tradition and values. Unlike Singapore, though, the U. S. today is a nation in search of a common culture, trying to be a universal society that assimilates the traditions of people from all over the world. Efforts to safeguard minority as well as individual rights have produced a gridlock in the justice system. Its troubles stem more from the decay of family life than from any government failures. Few societies can afford to look on complacently. As travel eases and cultures intermix, the American experience is becoming the world's. The circumstances of this affair--evidently no Singaporean has ever been punished under the Vandalism Act for defacing private property--suggest that Singapore has used Fay as an unwilling point man in a growing quarrel between East and West about human rights.

单选题成熟红细胞获得能量的唯一途径是

单选题大部分限制性内切酶识别的序列呈

单选题关于甘油磷脂合成原料的叙述，错误的是

单选题关于诱导契合学说，正确的是

单选题酶非竞争性抑制的动力学特点是

单选题在DNA 双螺旋结构中，互补碱基配对规律是