题目

47．下列有关实验的叙述，正确的是（   ） A．健康人的汗液能与双缩脲试剂发生紫色颜色反应 B．若在光学显微镜下观察到细胞质流动方向为逆时针，则该细胞质流动方向实际为顺时针 C．叶绿体中色素溶于酒精，可利用这一原理提取新鲜叶片中的叶绿体色素 D．用不同浓度的硝酸钾溶液处理植物细胞后，均能观察到质壁分离和自动复原现象4、The coyote(丛林狼).that elever animal of wide-open space .has come to the nation’s captial.In fact ,coyotes have spread to every comer of the United States,changing their behaviors to fit new envioronments and causing researchers to deal with a troublesome new kind of creature:the city coyote. The coyote originally lived in the middle of the continent.One of its most obvious characters is its smartness, which has made the animal a notorious（臭名昭著的） pest.Hunters trapped,shot and poisoned more than a million coyotes in the 1900s.It’s still one of America’s mosthunted animals. Yet the coyote has survived.How has the coyote shown this extraordinary ability?”I guess if you wanted to use one word,it’d be ‘plasticity’.”says Erie Gese,an expert at Utah State University. Coyotes can live alon, in pairs, or in large packs like wolves,hunt at night or during the day , occupy a small region or an area up to 40 square miles,and live on all sorts of food,from lizards（蜥蜴）and shoes, to ants and melons.     Unbelicvadly  people  helpcd coyotes  increase  when  they kiltcd most of the wolves in the United States. The sprcdding of coyotes into city areas,though.is rccent.They travel at night,crossing sidcwalks and bridges.running atong roads and ducking into cuinerts (钻入 洞and underpasscs .No one knows why coyotes are maving into cities.but expertsexplaih that clevcter,more human-tolerant(不怕人的)coyotes are teaching urban survivalskills to new generations. Occasionally.coyotes mighe attack human beings.There have been about 160 attacks on peoplc in reccnt years Therefore,people have bccn consistently told not feed coyotes or leave pct food unseeurcd.That ,plus a large trapping program in the neighborhood.has cur down on the coyote population. 1.The underlinged word “plasticity”in Paragraph 2refers to____________. A.the ability to fit the environment      B.notonous smartness C.hunting ability                    D.being human-tolerant                    2.The aim of the passage is to_____________. A.tell pcople how to fight against coyotes B.tell us why the coyote is the most hunted animal C.supply the reason why the coyote is a kind of motorious pest D.explain how the coyote has spread to and survived in cities                         3.According to the passage,coyote__________. A.originally lived in the west of the continent B.sleep dung the day but look for food at night C.are teaching survival skills to therr younger generations D.suffered a population deerease because pcople killed wolves                        4.According to the passage,to cut dowa on the coyolc population.people are advised to_______. A.leave pct food secured             B.keep coyotes in small regions C.foree coyotes to live alone          D.avond using trapping programs