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.
Melissa Mahan’s story is mentioned in the text to （）
A. show tourism of Netherlands is no better than that of US
B. introduce the topic of Location-based services by GPS
C. show that they are dissatisfied with traveling
D. explain the reason why they start a new company
参考答案：B
解析：
[直击题眼] 第二段开头：This is just one example of how GPS is being used…to tourists．
[深层剖析] 本题测试的是考生对文章第一段内容的理解以及作者的写作目的，从考点来看，与第一题相同。 [B]选项谈到“引出主题”这一概念，正符合题干。因此，[B]正确。本选项的难点在于有些同学认为Location-based services是在文章结尾提到的，而题干内容在文章开头，所以不敢选[B]。但文章主旨可以在文章中多次提到，只不过表达方式不同而已。
[主干扰项分析] [C]和[D]的意思与文章相符，但都是就事论事的选项，并未体现作者的写作目的。
[次干扰项分析] [A]选项在文中没有提及，错误较为明显，但考生需注意no more than和not more than的区别：前者的意思是“和…一样不”；后者的意思是“…不如…”。如：John is not better than Tom．约翰不如汤姆好。 John is no better than Tom．约矫和汤姆一样坏。