Question

As temperatures go up, bison（北美野牛）get smaller. Joseph Craine, research assistant professor in the Division of Biology at Kansas State University, examined how climate change during the next 50 years will affect grazing（放牧）animals such as bison and cattle in the Great Plains.

“Bison are one of our most important conservation animals and hold a unique role in grasslands in North America,” Craine said.  “In addition to their cultural and ecological significance, they’re economically important.  There are about half a million bison in the world.” Craine analyzed a data set of 290,000 weights, ages and sexes collected from 22 bison herds（兽群）throughout the U. S. The organizations kept annual records of each animal in the herd and matched the data with the climates of the sites.

Based on differences in sizes of bison across herds, Craine found that during the next 50 years, future generations of bison will be smaller in size and weigh less. Climate is likely to reduce the nutritional quality of grasses, causing the animals to grow more slowly.

“We know that temperatures are going to go up,” Craine said.  “We also know that warmer grasslands have grasses with less protein（蛋白质）, and we now know that warmer grasslands have smaller grazers. It all lines up to suggest that climate change will cause grasses to have less protein and cause grazers to gain less weight in the future.”

Craine said the results of climate change in coming decades can already be seen by comparing bison in cooler, wetter places with those in warmer, drier places. For example, the average 7-year-old male bison in South Dakota weighed 1, 900 pounds, while an average 7- year-old male bison in Oklahoma — a warmer place — weighed 1, 300 pounds.

“The difference in temperature between those two states is around 20 degrees Fahrenheit, which is about three times the projected increase in temperatures over the next 75 years,” Craine said. “It is a clear indicator that long-term warming will affect bison and is something that will happen across the U.S. over the next 50-75 years.”

1.In the next fifty years, researchers Say, bison will ________.

A. become smaller and lighter

B. disappear in the Great Plains

C. play a less important part

D. adapt to different climate changes

2.The underlined word “grazers” probably refers to ________.

A. the researchers  B. the grasses

C. the bison         D. the protein

3.What is the main reason for the bison to become smaller?

A. The deceasing amount of grass.

B. The rising temperature.

C. The rising number of bison.

D. The loss of weight.

4.Paragraph 5 is written as an example to show ________.

A. Craine’s prediction will come true in 50 years

B. bison are smaller than in the past

C. the nature balance is being destroyed

D. bison’s size is linked with different climate

Answer

1.A

2.C

3.B

4.D

【解析】

试题分析：这是一篇说明文。北美野牛的大小、体重与温度有关。随着温度的升高北美野牛会变的更小、更轻。

1.1】A细节理解题。根据第三段第一句Craine found that during the next 50 years, future generations of bison will be smaller in size and weigh less. Craine发现在接下来的50年里，野牛的后代将更小、更轻。故选A

2.2】C词义猜测题。根据第四段最后两句we now know that warmer grasslands have smaller grazers. It all lines up to suggest that climate change will cause grasses to have less protein and cause grazers to gain less weight in the future. 我们现在知道，温暖的草原有较小的食草动物。所有的线表明，气候变化将导致草有较少的蛋白质和导致食草动物在未来获得更少的重量。根据文章第一句As temperatures go up, bison（北美野牛）get smaller.随着温度升高，北美野牛变得更小。前后联系得知C项正确。

3.3】B细节理解题。根据文章第一句As temperatures go up, bison（北美野牛）get smaller.随着温度升高，北美野牛变得更小。故选B

4.4】D推理判断题。根据第五段For example, the average 7-year-old male bison in South Dakota weighed 1, 900 pounds, while an average 7- year-old male bison in Oklahoma — a warmer place — weighed 1, 300 pounds.例如，在南达科他州的平均7岁的雄性野牛重达1,900磅，而在俄克拉何马州的平均7岁的雄性野牛——一个温暖的地区，重达1,300磅。因为气候变暖，草有较少的蛋白质，引起北美野牛体重变轻、形状变小。第五段举此例就是为了说明北美野牛的大小与不同的气候有关系。所以选D

考点：考查说明文阅读。