单选题孕酮的化学性质是

单选题下述造成膝关节半月板损伤的必要因素哪项是不恰当的

单选题关于慢性阑尾炎的叙述，下列哪项不正确

单选题肠梗阻的诊断确立后，最重要的是明确

单选题 对脑垂体毗邻的描述，正确的是（ ） A、后方是鞍结节 B、上方隔薄层骨壁与鼻腔相靠 C、前方是鞍背 D、两侧为蝶窦 E、以上都不对

单选题必须紧急手术治疗的疝是（ ）

单选题恢复肺泡功能和功能残气量较为优越的通气模式是

单选题A．胃十二指肠溃疡 B．门静脉高压症C．出血性胃炎 D．肝肿瘤和肝外伤E．胃癌

单选题关于胆石症的叙述，不正确的是

单选题膜上尿道断裂时，尿外渗范围在

单选题腰麻后头痛常发生于麻醉后第几天

单选题早、中期食管癌常用的手术方法是

单选题腰腿痛和颈肩痛最常见的病因是

单选题When Melissa Mahan and her husband visited the Netherlands, they felt imprisoned by their tour bus. It forced them to see the city according to a particular route and specific schedule--but going off on their own meant missing out on the information provided by the guide. On their return home to San Diego, California, they started a new company called Tour Coupes. Now, when tourists in San Diego rent one of their small, brightly coloured three-wheeled vehicles, they are treated to a narration over the stereo system about the places they pass, triggered by Global Positioning System (GPS) satellite technology. This is just one example of how GPS is being used to provide new services to tourists. "What we really have here is a technology that allows people to forget about the technology," says Jim Carrier of IntelliTours, a GPS tourism firm which began offering a similar service over a year ago in Montgomery, Alabama. The city is packed with sites associated with two important chapters in American history, the civil war of the 1860s and the civil-rights movement a century later. Montgomery has a 120-year-old trolley system, called the Lightning Route, which circulates around the downtown area and is mainly used by tourists. On the Lightning Route trolleys, GPS-triggered audio clips point out historical hotspots. Other firms, such as CityShow in New York and GPS Tours Canada in Banff, Canada, offer hand-held GPS receivers that play audio clips for listening to while walking or driving. In South Africa, Europcar, a car-rental firm, offers a device called the Xplorer. As well as providing commentary on 2 000 points of interest, it can also warn drivers if they exceed the local speed limit. If such services prove popular, the use of dedicated audio-guide devices could give way to a different approach. A growing number of mobile phones have built-in GPS or can determine their locations using other technologies. Information for tourists delivered via phones could be updated in real time and could contain advertisements. "Location-based services", such as the ability to call up a list of nearby banks or pizzerias, have been talked about for years but have never taken off. But aiming such services at tourists makes sense--since people are more likely to want information when in an unfamiliar place. It could give mobile roaming a whole new meaning.

单选题化脓性关节炎早期诊断中，最有价值的方法是

单选题腹腔内空腔脏器破裂确诊后其治疗原则是

单选题下述哪项不是肾损伤的并发症

单选题A．神经源性间歇跛行B．坐骨神经支配区的放射痛C．两者均有D．两者均无

单选题肝的功能单位是

单选题急性肾盂肾炎多由大肠杆菌感染，首选的抗生素为