问题补充：
From theouterof New York to the heart of Singapore, nature is everywhere you’re not looking in some of Earth’s most crowded big cities. Outdoor adventure is often just a few stops on the train—or a short drive- away from theannoyingcrowds.Here are a few favorites to get you going:
Mount Hollywood Trail（林间小道，乡间小路） Los Angeles
It’s not a skyscraper or a Ferris wheel, and there’s no expensive restaurant up top. But if you want an absolutely unforgettable, no-admission-charged, 360-degree view of the entire Los Angeles region, it’s yours. All you have to do is walk a little. One of the preferred exercise routes, the Mount Hollywood Trail, is easily accessed from the parking lot of the famous GriffithObservatory; you see what you get at the end of this steep 1.5-mile trail, which winds its way through the Griffith Park wilds up to the mountain’s 1,640-foot peak.
Bronx River, New York
It may not be on your Top 10 list of things to do when you finally get to the Big Apple, but exploring the almost-secret river that flows through one of New York’s most mysteriousboroughs(自治市) is an unforgettable experience. The Bronx River Alliance, a non-profit group that has worked tirelessly to bring the much-abused river back to life , operates cycling and canoeing trips along the river, from the rugged Hunts Point section down near the harbor on up through the borough.
Southern Islands, Singapore
Believe it or not, tightly packedSingapore does have plenty of open space left. There are actual trails right in the middle of everything, if you know where to look. But to really get away from it all, the Southern Islands, a small group of little green dots just off the city state’s southern shoreline, are just the thing.
Lee Valley, London
This East London river valley changed last summer, when anyone near a television got an eyeful of Olympic Park, built directly in the middle of the valley. Inside the park, beautifully landscaped sections quickly became a favorite relaxation spot for games goers. At present, you’ll find miles of walking paths worth exploring. Start at the Waltham Cross train and follow the signposted walking route southbound, guiding you past important historic industrial areas, through interesting city neighborhoods, past the western side of Olympic Park and on to the Thames.
【小题1】If someone wants to enjoy an unforgettable experience for free , he can go to .A．Mount Hollywood Trail and Bronx RiverB．Mount Hollywood Trail and Southern IslandsC．Lee Valley and Southern IslandsD．Bronx River and Lee Valley【小题2】The writer of the passage wants to .A．inform the readers that nature exists in crowded big citiesB．appeal to more people to outdoor adventureC．recommend several historical spots to readersD．present various approach to outdoor adventure【小题3】We know from the passage .A．it’s difficult to find a proper trail in packed SingaporeB．the Thames is not far away from the East London river valleyC．The Bronx River Alliance has succeeded in running the riverD．you may have trouble reaching the Mount Hollywood TrailA
答案：
(答案→)A
解析：文章主要讲了即使世界上最拥挤的城市也会有大自然的存在，文章介绍了三个值得参观和做户外运动的地方。
【小题1】细节题;文章第二段的句子：But if you want an absolutely unforgettable, no-admission-charged, 360-degree view of the entire Los Angeles region, it’s yours.和第三段的The Bronx River Alliance, a non-profit group that has worked tirelessly to bring the much-abused river back to life , 可知Mount Hollywood Trail and Bronx River是免费的，选A
【小题2】主旨题：文章第一段的句子Outdoor adventure is often just a few stops on the train—or a short drive- away from theannoyingcrowds.可知走几站路或开很短的距离就可以远离恼人的人群，可知世界上最拥挤的城市也会有大自然的存在。选A
【小题3】细节题：从文章的最后一段This East London river valley changed last summer, when anyone near a television got an eyeful of Olympic Park, built directly in the middle of the valley. 可知泰晤士河和东伦敦河谷相距不远。选B
