中国av一区,日韩欧美一区二区三区久久婷婷,国产欧美va欧美va香蕉在线,国产精品18hdxxxⅹ在线

　　環(huán)球教育SAT考試頻道：今天為大家?guī)?lái)2016年4月28日SAT考試閱讀題附答案和解析，希望可以幫助到考生們。

　　SAT考試閱讀題目：Critical Reading>Select an Answer

　　Building a road through wilderness certainly has a visible impact on local flora and fauna—you're physically paving over a slice of what was once habitat. But roads have less obvious effects, too. Like the introduction of traffic noise, which also takes a toll. "You can see an oil spill but you can't see a traffic noise spill. So convincing people that it's important is a little more difficult," said Heidi Ware.

　　Ware is an ornithologist at the Intermountain Bird Observatory in Boise, Idaho. She and her colleagues studied the reactions by birds to the sounds of vehicles. And they did it without paving the great outdoors. Instead, they mounted 15 pairs of speakers on Douglas fir trees, along a ridge near Boise, and played traffic noise. They thus created what they call a "phantom road" through the wilderness, which boosted local noise levels 10 decibels higher than those in the surrounding forest.

　　Turns out just the sounds of traffic scared away a third of the area's usual avian visitors, and cut species diversity too. And birds of multiple species were not able to pack on as much fat to fuel their migrations, when they were forced to dine to the soundtrack of traffic.

　　Follow-up experiments in the lab found that, when it's noisy, birds spend a lot less time head down, pecking at food, and a lot more time scanning their surroundings.

　　Ware says Yosemite, Glacier and Rocky Mountain National Parks all have roads that are busy enough to produce these effects. And, short of closing park roads to traffic, she says things like rubberized asphalt and lower speed limits could help cut the noise. "Glacier National Park is going to put up signs, that instead of showing your speed and preventing people from speeding, it's going to show how loud their car is on the road." Which, hopefully, will continue to encourage wilderness lovers to leave no trace—visible or audible.

　　The primary purpose of the second paragraph is to __________

　　(A) establish the credentials of researchers who conducted an experiment.

　　(B) present a hypothesis a group of researchers set out to investigate.

　　(C) identify the locations of the sites where a study was conducted.

　　(D) outline the methodology researchers used in a study.

　　答案：D

　　解析：

　　Choice D is the best answer. In the second paragraph the author's main focus is on outlining the methods Ware and her colleagues used in their study. The author explains that the researchers used speakers to simulate a road that raised noise levels by 10 decibels in order to study birds' reactions to the noise.

　　更多閱讀：點(diǎn)擊近期SAT考題