单选题关于消化性溃疡的癌变，下列哪项是正确的A．各种消化性溃疡均有癌变可能B．癌变发生于溃疡边缘C．癌变率可达1%以上D．症状经严格的内科治疗无改善E．癌变率与年龄无关

单选题胆汁中的主要固体成分是

单选题女性，16岁，诊断病毒性心肌炎，心电图表现为完全性房室传导阻滞。其心脏听诊较有特征性的改变是

单选题Large, multinational corporations may be the companies whose ups and downs seize headlines. But to a far greater extent than most Americans realize, the economy's vitality depends on the fortunes of tiny shops and restaurants, neighborhood services and factories. Small businesses, defined as those with fewer than 100 workers, now employ nearly 60 percent of the work force and are expected to generate half of all new jobs between now and the year 2000. Some 1.2 million small firms have opened their doors over the past six years of economic growth, and 1989 will see an additional 200,000 entrepreneurs striking off on their own. Too many of these pioneers, however, will blaze ahead unprepared. Idealists will overestimate the clamor for their products or fail to factor in the competition. Nearly everyone will underestimate, often fatally, the capital that success requires. Midcareer executives, forced by a takeover or a restructuring to quit the corporation and find another way to support themselves, may savor the idea of being their own boss but may forget that entrepreneurs must also, at least for a while, be bookkeeper and receptionist, too. According to Small Business Administration data,24 of every 100 businesses starting out today are likely to have disappeared in two years, and 27 more will have shut their doors four years from now. By 1995,more than 60 of those 100 start-ups will have folded. A new study of 3,000 small businesses, sponsored by American Express and the National Federation of Independent Business, suggests slightly better odds: Three years after start-up, 77 percent of the companies surveyed were still alive. Most credited their success in large part to having picked a business they already were comfortable in. Eighty percent had worked with the same product or service in their last jobs. Thinking through an enterprise before the launch is obviously critical. But many entrepreneurs forget that a firm's health in its infancy may be little indication of how well it will age. You must tenderly monitor its pulse. In their zeal to expand, small-business owners often ignore early warning signs of a stagnant market or of decaying profitability. They hopefully pour more and more money into the enterprise, preferring not to acknowledge eroding profit margins that mean the market for their ingenious service or product has evaporated, or that they must cut the payroll or vacate their lavish offices. Only when the financial well runs dry do they see the seriousness of the illness, and by then the patient is usually too far gone to save. Frequent checks of your firm's vital signs will also guide you to a sensible rate of growth. To snatch opportunity, you must spot the signals that it is time to conquer new markets, add products or perhaps franchise your hot idea.

单选题男性患者，60岁，慢性阻塞性肺病15年，近1周咳喘加重，紫绀明显，烦躁，血气分析：pH7．4、PaO 2 40mmHg、PatCO 2 70mmHg，进行氧疗应采用

单选题女性，30岁，2周前有上呼吸道感染病史。2天来感心悸，胸痛伴乏力。查体：体温37．5℃，脉搏75次/分，血压100/70mmHg，咽稍红，扁桃体不大，心律规则，心率110次/分，心电图示室性心动过速。

单选题下列关于支气管扩张的叙述，不正确的是

单选题有关胃溃疡的特点，以下叙述正确的是

单选题男，62岁，经丙硫氧嘧啶治疗1.5年后甲状腺较前缩小。T 3 抑制试验：3小时抑制率>50％，24小时抑制率>50％，TT 3 、TT 4 正常。对此病人应作的处理是

单选题下列选项属于抗ENA抗体的是

单选题支气管扩张患者施行体位引流排痰，下列哪项不正确( )(1996年)

单选题下列哪项是急性肾炎与慢性肾炎的重要鉴别特征

单选题下列关于促胰液素生理作用的叙述，错误的是( )(2010年)

单选题患者，女，17岁，面部蝶形红斑1年，伴双手指关节、腕关节疼痛，经检查诊断为SLE。请问下列哪一种自身抗体是SLE的标记性抗体

单选题二尖瓣关闭不全与二尖瓣脱垂鉴别要点是

单选题诊断肺癌首选的检查方法是

单选题A．肝铁含量增加B．lgA升高C． 血清铜蓝蛋白降低D．胆固醇升高E．抗核抗体阳性

单选题系统性红斑狼疮有关补体C3的描述正确的是

单选题A．肥厚型心肌病B．退行性主动脉瓣狭窄C．先天性二尖瓣畸形D．风湿性心脏病主动脉瓣狭窄E．室间隔缺损

单选题胃溃疡大出血易发生在哪个部位