One study was done by researchers at California Polytechnic State University. A research team studied the effects of birdsong on people walking through a park in the state of Colorado, U. S. A biology graduate student, Danielle Ferraro, led the study. Ferraro says that there could be an evolutionary(进化的) reason why we like birdsong. There could be many other reasons, too. Ferraro states that in some areas around the world birdsong can also signal the arrival of spring and nice weather. Bird diversity, she adds, can also mean a healthy environment.
She explained her study to VOA. Ferraro and her team played recorded songs from a diverse group of birds native to the area. They did this on hiking trails in a park in Boulder, Colorado.
Over several weeks, the researchers played recorded birdsong at certain time of the day and other time they did not. Then they talked with hikers after they passed by. Hikers who heard the recorded diverse birdsong reported a greater sense of well-being than those who heard simply the natural birds. The research suggests that both the bird sounds and biodiversity(生物多样性) can increase feelings of well-being.
Ferraro explained that she used native birdsong for the study. This way it would sound as natural as possible. They also did the study during the summer. “The study took place in the summer and that's kind of important because the spring is most birds’ breeding season. And if we played the birdsong during breeding season, you know, it would be terrible. ”
Scientists in Germany also examined for the first time whether a diverse nature also increases human well-being across Europe. They found that the happiest Europeans are those who can experience many different kinds of birds in their daily life, or who live in near-natural surroundings that are home to many species.
“I recommend planting native trees and flowers because we have a lot of, you know, pretty ornamental (装饰性的) plants in our cities. So, I think it's important to have species that are native to the area to increase bird diversity. ” Joel Methorst, the study's lead author said.
8. What can we learn from the study led by Danielle Ferraro about birdsong?
A. It can make us humans happy.     B. It means a healthy environment.
C. It signals the arrival of danger.     D. It tells us the evolution of birds.
9. Why was the study conducted in the summer according to Ferraro?
A. To get more exact data.         B. To please the hikers.
C. To reduce disturbance to birds’ breeding.     D. To have more birds involved in the study.
10. Why were scientists in Germany mentioned in the text?
A. To introduce a new topic for discussion.     B. To support the recent finding further.
C. To add some background information.     D. To summarize the previous paragraphs.
11. What can be advised to increase bird diversity from Joel Methorst?
A. Introducing more foreign birds.     B. Expanding the habitat of birds.
C. Planting more trees in the cities.     D. Having more native species.
8-11.ACBD
【文章大意】本文是一篇说明文,，调查研究表明鸟儿的歌唱能改善人的情绪，让人高兴。
8. 【答案】A
【解析】细节理解题。根据第一段A research team studied the effects of birdsong on people walking through a park in the state of Colorado, U. S. 并结合第三段The research suggests that both the bird sounds and biodiversity(生物多样性) can increase feelings of well-being. 可知，调查研究发现鸟儿的歌唱能改善人的情绪，让人高兴。
9. 【答案】C
【解析】细节理解题。根据第四段“The study took place in the summer and that's kind of important because the spring is most birds’ breeding season. And if we played the birdsong during breeding season, you know, it would be terrible. ”可知，春天是鸟儿的繁殖季节，所以这个调查选择在夏天，是为了减少对鸟儿繁殖的干扰。
10. 【答案】B
【解析】推理判断题。根据第三段The research suggests that both the bird sounds and biodiversity(生物多样性) can increase feelings of well-being. 再结合倒数第二段Scientists in Germany also examined for the first time whether a diverse nature also increases human well-being across Europe. 可知，提及德国科学家的研究发现的目的在于进一步支持第一个研究的结论。
11 . 【答案】D
【解析】细节理解题。结合最后一段So, I think it's important to have species that are native to the area to increase bird diversity. 可知，Joel Methorst 的观点是有更多的当地物种可以有效地增加鸟儿的种类。