单选题兴奋-收缩耦联中起关键作用的离子是( ) A．Na+ B．K+ C．Ca2+ D．Cl-

单选题患者男性，40岁，背部红、肿、热、痛7天，表面有三、四个破口，流黄色汁液。其病变由

单选题If you smoke, you'd better hurry. From July 1st pubs all over England will, by law, be no-smoking areas. So will restaurants, offices and even company cars, if more than one per-son uses them. England's smokers are following a well-trodden path. The other three bits of the United Kingdom have already banned smoking in almost all enclosed public spaces, and there are anti-smoking laws of varying strictness over most of Western Europe. The smoker' s journey from glamour through toleration to suspicion is finally reaching its end in pariah status. But behind this public-health success story lies a darker tale. Poorer people are much more likely to smoke than richer ones—a change from the 1950s, when professionals and la-borers were equally keen. Today only 15% of men in the highest professional classes smoke, but 42% of unskilled workers do. Despite punitive taxation—20 cigarettes cost around ￡ 5.00 ($10.00), three-quarters of which is tax—55% of single mothers on benefits smoke. The figure for homeless men is even higher; for hard-drug users it is practically 100% . The message that smoking kills has been heard, it seems, but not by all. Having defeated the big killers of the past—want, exposure, poor sanitation—governments all over the developed world are turning their attention to diseases that stem mostly from how individuals choose to live their lives. But the same deafness afflicts the same people when they are strongly encouraged to give up other sorts of unhealthy behavior. The lower down they are on practically any pecking order—job prestige, income, education, background-the more likely people are to be fat and unfit, and to drink too much. That tempts governments to shout ever louder in an attempt to get the public to listen and nowhere do they do so more aggressively than in Britain. One reason is that pecking orders matter more than in most other rich countries: income distribution is very unequal and the unemployed, disaffected, ill-educated rump is comparatively large. Another reason is the frustration of a government addicted to targets, which often aim not only to improve some-thing but to lessen inequality in the process. A third is that the National Health Service is free to patients, and paying for those who have arguably brought their ill-health on themselves grows alarmingly costly. Britain' s aggressiveness, however, may be pointless, even counter-productive. There is no reason to believe that those who ignore measured voices will listen to shouting. It irritates the majority who are already behaving responsibly, and it may also undermine all government pronouncements on health by convincing people that they have an ultra-cautious margin of error built in. Such hectoring may also be missing the root cause of the problem. According to Mr. Marmot, who cites research on groups as diverse as baboons in captivity, British civil servants and Oscar nominees, the higher rates of ill health among those in more modest walks of life can be attributed to what he calls the "status syndrome". People in privileged positions think they are worth the effort of behaving healthily, and find the will-power to do so. The implication is that it is easier to improve a person's health by weakening the connection between social position and health than by targeting behavior directly. Some public-health experts speak of social cohesion, support for families and better education for all. These are bigger undertakings than a bossy campaign; but more effective, and quieter.

单选题下列不符合肝硬化腹水形成原因的描述是

单选题寄生虫感染时，病灶内最多见的炎症细胞是

单选题具有体温调定点作用的中枢位于

单选题不符合三尖瓣狭窄的是

单选题不能引起血管平滑肌舒张的物质是

单选题支气管哮喘病人呼气比吸气更为困难，其原因是

单选题纤维素样坏死病变内不出现

单选题心脏肥大是指

单选题25－OH－VD 3 转变为1，25－(OH) 2 －VD 3 是在下列哪个器官进行的

单选题临床上较为多见的色盲是______

单选题下列关于体温正常变动的叙述，正确的是

单选题风湿病出现的坏死为

单选题下列凝血因子中，不是蛋白质的是

单选题恶性葡萄胎与葡萄胎的主要区别是

单选题BRCA－1基因突变可导致

单选题 大量饮水后尿量增多，即所谓的水利尿，主要原因是（ ） A、醛固酮分泌减少 B、ADH分泌减少 C、血浆胶体渗透压增加 D、肾小囊压力减少

单选题肉芽肿性炎症中的上皮样细胞来自