单选题 .  Questions 19 to 21 are based on the passage you have just heard.
4. 
【正确答案】 B
【答案解析】[听力原文]
   Welcome to Yellow Stone National Park. Before we begin our nature walk today, I'd like to give you a short history of our national park service. The national park service began in the late 1800s. A small group of explorers had just completed a month-long exploration of the region that is now Yellow Stone. They gathered around the campfire and after hours of discussion, they decided that they should not claim this land for themselves. They felt it should be accessible to everyone. So they began a campaign to preserve this land for everyone's enjoyment. Two years later, in the late 19th century, an Act of Congress signed by President Ulysses S. Grant, proclaimed the Yellow Stone region a public park. It was the first national park in the world. After Yellow Stone became a public park, many other areas of great scenic importance were set aside. And in 1916 the national park service was established to manage these parks. As a park ranger, I am an employee of the national park service. In the national park, park rangers are on duty at all the time to answer questions and help visitors in any difficulty. Nature walks, guided tours and campfire talks are offered by specially trained staff members. The park service also protects the animals and plants within the parks.
   Q: According to the speaker, who originated the idea of the public park?
欢迎来到黄石国家公园。在我们开始今天的野外散步前,请允许我为大家简要介绍一下国家公园管理局的历史。国家公园的服务始于19世纪末。一小队探险家当时刚刚完成了一次为期一个月的探险,他们探索的区域便是今天的黄石国家公园。这些探险家围坐在营火旁,经过了几个小时的讨论之后,他们做出决定不应该声称这片区域为自己所专有。他们认为每个人都应该能来到这里,所以他们开始了保留该区域开放权的活动,以便使每个人都可以到此游玩。两年之后,在19世纪末,由尤里西斯-辛普森·格兰特总统签署的国会法案宣布,黄石国家公园正式成为一座公共公园。黄石国家公园是全世界第一座国家公园。然而,在黄石成为公共公园之后,这处伟大风景名胜中的其他许多地区却被置于一旁。于是,在1916年,为了对这些公园进行管理,国家公园管理局正式成立。作为一名公园管理员,我也是国家公园管理局的一员。在国家公园里,公园管理员负责随时解答人们的问题,并在他们遇到任何困难的时候提供帮助。野外散步、指引游览和营火谈话等工作是由一些受过专门训练的职员来负责的。公园管理局也会保护公园里的动植物。
   快速浏览各题选项,根据Congress、explorers、President、national park、explored、scientific studies、nature walks等关键词可知,短文可能介绍与国家公园有关的一些信息,再由各题选项的特征可大致推测需留意与人物、定义、目的有关的信息。
   四项均为名词短语,且均指代人的身份。可能问什么人做了什么事。
   题干问是什么人最先提出了设立国家公园的想法。听力短文在开头提到,国家公园的服务始于19世纪晚期,当时有一小组的探险家刚刚完成了对现在黄石公园所在区域的探险,他们在营火旁围坐,经过了几个小时的讨论,他们做出决定不应该声称这片区域为他们所专有,认为每个人都应该能来到这里,所以他们开始宣传要保护这个区域,以便每个人都可以到此游玩。可见,是一些探险家最初提出了设立国家公园并向公众开放的建议。故选B。