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.

单选题腹腔内空腔脏器破裂确诊后其治疗原则是

单选题下列各项不是肺癌手术治疗禁忌症的是

单选题关于无菌术的叙述中，下列哪项是正确的( )(1991年)

单选题下列关于麻醉前患者准备的叙述，错误的是A．合并高血压者应控制在180/100mmHg以下较为安全B．合并急、慢性肺部感染者，应用有效抗生素3～5天C．有心衰史、房颤或心脏明显扩大者，术前3天应停用洋地黄类药物D．糖尿病者空腹血糖不高于8.3mmol/LE．小儿术前应禁食4～8小时，禁水2～3小时

单选题下述哪项不是肾损伤的并发症

单选题化脓性关节炎早期诊断中，最有价值的方法是

单选题能确定食管癌已外侵的是

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A．chest CT examination(胸CT检查)B．regular chest X-ray examination(定期胸X线检查)C．B type ultrasound echogram[B型超声回波图(B超)]D．fiberbmnchoscopy(纤维气管)E．expeCTorativecytology(痰液细胞学)

单选题患者，男性，12岁，被汽车轧伤左大腿，左下肢痛，不敢活动。检查：神志清，表情淡漠，面色苍白，脉搏细弱，大腿中段皮肉裂开，骨端外露。应考虑合并有

单选题男性，40岁，发热、流涕3天，继以恶心、呕吐，少尿，乏力，血压160／100mmHg，血红蛋白70g／L。血肌酐707．2μmol／L，尿素氮57mmol／L，血浆白蛋白48g／L．B超双肾长轴约8cm。本例最可能诊断为

单选题A．半月线B．白线C．齿状线D．肛窦

单选题癌变可能性最小的直肠息肉是

单选题急性肾盂肾炎多由大肠杆菌感染，首选的抗生素为

单选题肝的功能单位是

单选题大面积烧伤最主要的死因是

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单选题下列哪项不是导致下腰痛的诱因( )(1992年)

单选题最可能导致急性肾衰竭的损伤是