单选题At some point during their education, biology students are told about a conversation in a pub that took place over 50 years ago. J. B. S. Haldane, a British geneticist, was asked whether he would lay down his life for his country. After doing a quick calculation on the back of a napkin, he said he would do so for two brothers or eight cousins. In other words, he would die to protect the equivalent of his genetic contribution to the next generation. The theory of kin selection--the idea that animals can pass on their genes by helping their close relatives--is biology's explanation for seemingly altruistic acts. An individual carrying genes that promote altruism might be expected to die younger than one with "selfish" genes, and thus to have a reduced contribution to the next generation's genetic pool. But if the same individual acts altruistically to protect its relatives, genes for altruistic behavior might nevertheless propagate. Acts of apparent altruism to non-relatives can also be explained away, in what has become a cottage industry within biology. An animal might care for the offspring of another that it is unrelated to because it hopes to obtain the same benefits for itself later on (a phenomenon known as reciprocal altruism). The hunter who generously shares his spoils with others may be doing so in order to signal his superior status to females, and ultimately boost his breeding success. These apparently selfless acts are therefore disguised acts of self interest. All of these examples fit economists' arguments that Homo sapiens is also Homo economicus--maximizing something that economists call utility, and biologists fitness. But there is a residuum of human activity that defies such explanations: people contribute to charities for the homeless, return lost wallets, do voluntary work and tip waiters in restaurants to which they do not plan to return. Both economic rationalism and natural selection offer few explanations for such random acts of kindness. Nor can they easily explain the opposite: spiteful behavior, when someone harms his own interest in order to damage that of another. But people are now trying to find answers. When a new phenomenon is recognized by science, a name always helps. In a paper in Human Nature, Dr Fehr and his colleagues argue for a behavioral propensity they call "strong reciprocity". This name is intended to distinguish it from reciprocal altruism. According to Dr Fehr, a person is a strong reciprocator if he is willing to sacrifice resources to be kind to those who are being kind, and to punish those who are being unkind. Significantly, strong reciprocators will behave this way even if doing so provides no prospect of material rewards in the future.

单选题《脉经》载脉多少种

单选题小儿指纹浮现者．多属

单选题面色随四时不同而微有变化，秋天的面色相应为

单选题患者腹痛，便泄，日行七八次，粪质粘稠而臭，肛门灼热，小便短赤，身热，口渴，舌红，苔黄腻，脉滑数，可拟诊为

单选题A．喘B．哮C．上气D．短气

单选题大便先干后溏属于

单选题除哪项外，均为神气不足的表现A．健忘B．精神不振C．焦虑恐惧D．面色少华

单选题A．燥邪 B．湿邪 C．暑邪 D．寒邪

单选题代脉的脉象特征是A．缓而时止，止有定数B．数而时止，止无定数C．缓而时止，止无定数D．数而时止，止有定数

单选题A．舌体的颜色B．舌苔的厚薄C．舌体的动态D．舌苔的颜色

单选题A．无冲和之意，应指坚搏B．脉律无序C．脉形散乱D．虚大无根或虚弱不应指

单选题结脉和促脉的区别在于

单选题下列表现中不属卫分证的是

单选题面色黄而虚浮，称为

单选题A．黄芪建中汤B．小建中汤C．大建中汤D．当归建中汤

单选题以下除哪项外，均与假神有关A．精亏神衰B．临终前的预兆C．回光返照D．残灯复明

单选题患者，男，50岁。眩晕欲仆，头摇而痛，项强肢颤，腰膝酸软，舌红苔薄白，脉弦有力。其病机是

单选题A．真寒假热证B．真热假寒证C．表热里寒证D．表寒里热证

单选题A．《二因方》B．《察病指南》C．《诊家枢要》D．《世医得效方》