Cities usually have a good reason for being where they are, like a nearby port or river. People settle in these places because they are easy to get to and naturally suited to communications and trade. New York City, for example, is near a large harbour at the mouth of the Hudson River. Over 300 years its population grew gradually from 800 people to 8 million. But not all cities develop slowly over a long period of time. Boom towns grow from nothing almost overnight. In 1896, Dawson, Canada, was unmapped wilderness(荒野). But gold was discovered there in 1897, and two years later, it was one of the largest cities in the West, with a population of 30,000.
Dawson did not have any of the natural conveniences of cities like London or Paris. People went there for gold. They travelled over snow-covered mountains and sailed hundreds of miles up icy rivers. The path to Dawson was covered with thirty feet of wet snow that could fall without warming. An avalanche(雪崩) once closed the path, killing 63 people. For many who made it to Dawson, however, the rewards were worth the difficult trip. Of the first 20,000 people who dug for gold, 4,000 got rich. About 100 of these stayed rich men for the rest of their lives.
But no matter how rich they were, Dawson was never comfortable. Necessities like food and wood were very expensive. But soon, the gold that Dawson depended on had all been found. The city was crowded with disappointed people with no interest in settling down, and when they heard there were new gold discoveries in Alaska, they left Dawson City as quickly as they had come. Today, people still come and go — to see where the Canadian gold rush happened. Tourism is now the chief industry of Dawson City — its present population is 762.
48．What attracted the early settlers to New York City?
A．Its business culture.
B．Its small population.
C．Its geographical position.
D．Its favourable climate.
49．What do we know about those who first dug for gold in Dawson?
A．Two-thirds of them stayed there.
B．One out of five people got rich.
C．Almost everyone gave up.
D．Half of them died.
50．What was the main reason for many people to leave Dawson?
A．They found the city too crowded.
B．They wanted to try their luck elsewhere.
C．They were unable to stand the winter.
D．They were short of food.
51．What is the text mainly about?
A．The rise and fall of a city.
B．The gold rush in Canada.
C．Journeys into the wilderness.
D．Tourism in Dawson.
48．C
49．B
50．B
51．A
【分析】
这是一篇说明文。文章主要介绍了Dawson这座城市的发展原因、过程与现状。
48．细节理解题。根据文章第一段中Cities usually have a good reason for being where they are, like a nearby port or river. People settle in these places because they are easy to get to and naturally suited to communications and trade. New York City, for example, is near a large harbour at the mouth of the Hudson River.可知，人们选择在河边或港口设城是因为交通方便，便于做生意。而纽约就是在哈德森河口附近的一个大港口，故纽约吸引早期移民的原因是它的地理位置，故C正确。
49．细节理解题。根据文章第二段最后一句Of the first 20,000 people who dug for gold, 4,000 got rich. About 100 of these stayed rich men for the rest of their lives.可知，在最初挖黄金的两万人中有4000人变富有，所以是五分之一的人变富了，故B正确。
50．细节理解题。根据文章最后一段中and when they heard there were new gold discoveries in Alaska, they left Dawson City as quickly as they had come.可知，人们离开Dawson的主要原因是听说在Alaska发现了黄金，也就是他们要去别的地方寻找发财的机会。故B正确。
51．主旨大意题。第一段简要介绍城市发展的原因，引出Dawson这一城市的兴起，第二段介绍了该城市兴起的原因，第三段介绍人们选择离开该城市的原因及现在的状况，所以全文围绕Dawson这个城市的发展起伏。故A正确。
【点睛】主旨大意题的解题技巧：一篇文章都是围绕着一个中心思想或一个话题展开的，因此，有的文章中最明显的特点之一是有一个反复出现的中心词，即高频词，也叫做主题词。抓住了它，便容易抓住文章的中心。通读全文可知，文章主要围绕Dawson的发展展开，Dawson反复出现，再根据每一段的段首句可以总结出，文章第一段通过城市发展的原因引出Dawson，第二段介绍Dawson发展的原因，第三段介绍人们选择离开该城市的原因及现在的状况，从而总结出文章的主旨大意。