Question

【題目】 The past 70 years have been good for corn production in the Midwestern United States, with yields increasing fivefold since the 1940s. Much of this improvement has been credited to advances in farming technology but researchers at Harvard University are asking if changes in climate and local temperature may be playing a bigger role than previously thought.

In a newspaper, researchers find that a prolonged(延長(zhǎng)的) growing season due to increased temperatures, combined with the natural cooling effects of large fields of plants, have had a major contribution to improved corn production in the U.S. “Our research shows that improvements in crop yields depend, in part, on improvements in climate,” said Peter Huybers, professor of Earth and Planetary Sciences. “In this case, changing temperatures have had a beneficial impact on agricultural production, but there is no guarantee that benefit will last as the climate continues to change.

Understanding the detailed relationships between climate and crop yields is important as we move towards feeding a growing population on a changing planet. ” The researchers modeled the relationship between temperature and crop yields from 1981 to 2017 across the so-called Corn Belt. They found that as temperatures increased due to global climate change, planting days got earlier and earlier, shifting by about three days per decade. Early planting means the corn has more time to mature before the end of the growing season.

There is also a second, more surprising trend that has benefited corn yields. Whereas the vast majority of temperatures have warmed over the last century, the hottest days during the Midwestern growing season have actually cooled.

The researchers estimate that more than one quarter of the increase in crop yields since 1981 can be attributed to the twin effects of a longer growing season and less exposure to high temperatures, suggesting that the crop yield is more vulnerable to climate change than previously thought.

The researchers also show that the planting and harvest dates farmers currently use is significantly better adapted to the present climate than it would be to climates in earlier decades.

【1】What is previously thought to be the reason for the increase of corn production?

A.Local temperature change.B.Advanced farming technology.

C.Climate change.D.Production efficiency.

【2】Why is it important to understand the relationships between climate and crop yield?

A.The climate has a beneficial impact on agriculture.

B.We can change the climate to improve crop yield.

C.We depend on the climate to get food.

D.Crop yield relies less on the climate.

【3】How many factors that benefit corn yields are mentioned in the text?

A.4.B.3.

C.2.D.1.

【4】What is the main purpose of the text?

A.To explain a mystery.B.To question a common sense.

C.To show a new trend.D.To introduce a research result.

Answer 1

【答案】

【1】B

【2】C

【3】C

【4】D

【解析】

這是一篇說(shuō)明文。文章介紹一項(xiàng)研究結(jié)果。在這種情況下，不斷變化的氣溫對(duì)農(nóng)業(yè)生產(chǎn)產(chǎn)生了有益的影響，但不能保證這種影響將隨著氣候的持續(xù)變化而持續(xù)下去。

【1】

推理判斷題。根據(jù)第一段中Much of this improvement has been credited to advances in farming technology but researchers at Harvard University are asking if changes in climate and local temperature may be playing a bigger role than previously thought.“這種進(jìn)步很大程度上歸功于農(nóng)業(yè)技術(shù)的進(jìn)步，但哈佛大學(xué)的研究人員提出了一個(gè)問(wèn)題:氣候和當(dāng)?shù)販囟鹊淖兓�是否在其中發(fā)揮了比之前認(rèn)為的更大的作用?”由此可知，以前認(rèn)為玉米產(chǎn)量增加的原因是“先進(jìn)的農(nóng)業(yè)技術(shù)�！惫蔬xB。

【2】

細(xì)節(jié)理解題。根據(jù)第二段中Our research shows that improvements in crop yields depend, in part, on improvements in climate,“我們的研究表明，作物產(chǎn)量的提高在一定程度上取決于氣候的改善，”由此可知，之所以理解氣候和作物產(chǎn)量之間的關(guān)系很重要，是因?yàn)槲覀円揽繗夂颢@取食物。故選C。

【3】

細(xì)節(jié)理解題。根據(jù)第二段最后一句In this case, changing temperatures have had a beneficial impact on agricultural production, but there is no guarantee that benefit will last as the climate continues to change.“在這種情況下，不斷變化的氣溫對(duì)農(nóng)業(yè)生產(chǎn)產(chǎn)生了有益的影響，但不能保證這種影響將隨著氣候的持續(xù)變化而持續(xù)下去。”再根據(jù)第四段There is also a second, more surprising trend that has benefited corn yields. Whereas the vast majority of temperatures have warmed over the last century, the hottest days during the Midwestern growing season have actually cooled.“還有另一個(gè)更令人驚訝的趨勢(shì)有利于玉米產(chǎn)量。盡管上個(gè)世紀(jì)大部分地區(qū)的氣溫都有所上升，但中西部生長(zhǎng)季節(jié)最熱的日子實(shí)際上變冷了。”由此可知，文中提到了2個(gè)有利于玉米產(chǎn)量的因素。故選C。

【4】

目的意圖題。根據(jù)第二段中In a newspaper, researchers find that a prolonged(延長(zhǎng)的) growing season due to increased temperatures, combined with the natural cooling effects of large fields of plants, have had a major contribution to improved corn production in the U.S.“研究人員在一份報(bào)紙上發(fā)現(xiàn)，由于氣溫升高而延長(zhǎng)的生長(zhǎng)季節(jié)，加上大面積種植的自然降溫效應(yīng)，對(duì)美國(guó)玉米產(chǎn)量的提高做出了重大貢獻(xiàn)”。由此可知這篇文章介紹了一項(xiàng)研究結(jié)果。故選D。