31. What is the best title for the text?

　　A. Flying Car at Auto Show B. The Transition's First Flight

　　C.Pilots' Dream Coming True D. Flying Car Closer to Reality

　　【文章大意】本文是一篇说明文。主要介绍了Terrafugia公司研制出了飞车，试飞成功，预计将于明年进行销售。本文主要对飞车的历史由来及其构架进行了介绍。

29.C 【解析】细节理解题。根据"But don't expect it to show up in too many driveways. It's expected to cost

　　　$279,000"可知，因为Transition 的价格较高，所以不太可能在太多的马路上出现。故选C。

30.B 【解析】细节理解题。根据"he government has already permitted the company to use special materials to

make it easier for the vehicle to fly"以及"Mann said Terrafugia was helped by the Federal Aviation Administration's decision five years ago to create a separate set of standards for light sport aircraf"可知，政府对于飞车的研发是比较支持的。故选B。

31.D 【解析】标题归纳题。浏览全文，主要从飞车的试飞成功、飞车的构架以及多年以前人们对飞车的

　　　设想至今成为现实展开说明。故选D。

Passage2(2017·新课标全国卷III)

　　After years of heated debate, gray wolves were reintroduced to Yellowstone National Park. Fourteen wolves were caught in Canada and transported to the park. By last year, the Yellowstone wolf population had grown to more than 170 wolves.

　　Gray wolves once were seen here and there in the Yellowstone area and much of the continental United States, but they were gradually displaced by human development. By the 1920s, wolves had practically disappeared from the Yellowstone area. They went farther north into the deep forests of Canada, where there were fewer humans around.

The disappearance of the wolves had many unexpected results. Deer and elk populations - major food sources (来源) for the wolf - grew rapidly. These animals consumed large amounts of vegetation (植被), which reduced plant diversity in the park. In the absence of wolves, coyote populations also grew quickly. The coyotes