Winter begins in the north on December 22nd. People and animals have been doing what they

Winter begins in the north on December 22nd. People and animals have been doing what they always do to prepare for the colder months. Squirrels (松鼠), for example, have been busy gathering nuts from trees. Well, scientists have been busy gathering information about what the squirrels do with the food they collect.
They examined differences between red squirrels and gray squirrels in the American state of Indiana. The scientists wanted to know how these differences could affect the growth of black walnut (黑胡桃) trees. The black walnut is the nut of choice for both kinds of squirrels. The black walnut tree is also a central part of some hardwood forests.
Rob Swihart of Purdue University did the study with Jake Goheen, a former Purdue student now at the University of New Mexico. The two researchers estimate that several times as many walnuts grow when gathered by gray squirrels as compared to red squirrels. Gray squirrels and red squirrels do not store nuts and seeds in the same way. Gray squirrels bury nuts one at a time in a number of places. But they seldom remember where they buried every nut. So some nuts remain in the ground. Conditions are right for them to develop and grow the following spring. Red squirrels, however, store large groups of nuts above ground. Professor Swihart calls “death traps for seeds”.
Gray squirrels are native to Indiana. But Professor Swihart says their numbers began to decrease as more forests were cut for agriculture. Red squirrels began to spread through the state during the past century.
The researchers say red squirrels are native to forests that stay green all year, unlike walnut trees. They say the cleaning of forest land for agriculture has helped red squirrels invade Indiana. Jake Goheen calls them a sign of an environmental problem more than a cause.
【小题1】The study done by Rob Swihart and Jake Goheen is to .A．find out the living conditions for squirrelsB．do something to get rid of squirrelsC．learn squirrels’ influence on black walnut treesD．save the forests in the American state of Indiana【小题2】The difference between gray squirrels and red squirrels mainly lies in .A．the way they gather the walnutB．the place they store the walnutsC．the time they have winter sleepD．the place they have winter sleep【小题3】When Professor Swihart says “death traps for seeds”, he actually means that . A．nuts above the ground will not develop into plantsB．red squirrels eat more nuts than gray squirrelsC．gray squirrels and red squirrels will have severe fightsD．seeds can be traps for other animals in the forest【小题4】According to the passage, which of the following is true?A．Gray squirrels do more harm to the forest than red squirrels.B．Red squirrels and gray squirrels have helped the spread of walnut trees.C．The cleaning of forest land benefits red squirrels directly.D．The black walnut is equally attractive to both gray and red squirrels.C

(答案→)C 解析：文章讲述了红松鼠和灰松鼠的生活习性以及它们的不同生活方式给环境带来的影响。【小题1】细节题：根据第二段第二句“The scientists wanted to know how these differences could affect the growth of black walnut (黑胡桃) trees.”可知，科学家Rob Swihart and Jake Goheen研究红松鼠和灰松鼠以查明它们的生活习惯会对黑胡桃的生长产生什么样的影响。故选C。【小题2】细节题：根据第三段的“Gray squirrels and red squirrels do not store nuts and seeds in the same way.”可知，它们储藏坚果和种子的方法不一样。故选B。【小题3】细节题：根据第三段最后一行“store large groups of nuts above ground”可知，坚果埋在一个坑里的话，不容易成活。故选A。【小题4】细节题：根据第二段第二行的“as many walnuts grow when gathered by gray squirrels as compared to red squirrels”可知，红松鼠和灰松鼠都喜欢黑胡桃，D正确。

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