发布时间 : 星期二 文章2020届高考英语二轮复习600分冲刺优练专题1阅读理解考点2推理判断题学案更新完毕开始阅读ee6bcd0a4a2fb4daa58da0116c175f0e7cd1190b
第一编 专题一 考点2
[层级一 真题题组]
A
(2019·天津卷，C)
How does an ecosystem(生态系统) work？What makes the populations of different species the way they are？Why are there so many flies and so few wolves？To find an answer，scientists have built mathematical models of food webs，noting who eats whom and how much each one eats.
With such models，scientists have found out some key principles operating in food webs.Most food webs，for instance，consist of many weak links rather than a few strong ones.When a predator (掠食动物) always eats huge numbers of a single prey(猎物)，the two species are strongly linked；when a predator lives on various species，they are weakly linked.Food webs may be dominated by many weak links because that arrangement is more stable over the long term.If a predator can eat several species，it can survive the extinction (灭绝) of one of them.And if a predator can move on to another species that is easier to find when a prey species becomes rare，the switch allows the original prey to recover.The weak links may thus keep species from driving one another to extinction.
Mathematical models have also revealed that food webs may be unstable，where small changes of top predators can lead to big effects throughout entire ecosystems.In the 1960s，scientists proposed that predators at the top of a food web had a surprising amount of control over the size of populations of other species—including species they did not directly attack.
And unplanned human activities have proved the idea of top－down control by top predators to be true.In the ocean，we fished for top predators such as cod on an industrial scale，while on
land，we killed off large predators such as wolves.These actions have greatly affected the ecological balance.
Scientists have built an early－warning system based on mathematical models.Ideally，the system would tell us when to adapt human activities that are pushing an ecosystem toward a breakdown or would even allow us to pull an ecosystem back from the borderline.Prevention is key，scientists say，because once ecosystems pass their tipping point (临界点)，it is remarkably difficult for them to return.
文章大意：主题：人与自然(环境保护)；话题：食物网。本文是一篇说明文，文章主要介绍了科学家通过建立一个数学模型找到了管理食物网的几个主要原则。
1．What have scientists discovered with the help of mathematical models of food webs？_B__ A．The living habits of species in food webs. B．The rules governing food webs of the ecosystems. C．The approaches to studying the species in the ecosystems. D．The differences between weak and strong links in food webs.
解析：细节理解题。第二段第一句“With such models，scientists have found out some key principles operating in food webs.”中的principles与选项B中的rules相对应，故选B。
2．A strong link is found between two species when a predator _C__. A．has a wide food choice B．can easily find new prey C．sticks to one prey species D．can quickly move to another place
解析：细节理解题。注意本题中涉及的是a strong link。根据第二段第三句“When a predator always eats huge numbers of a single prey，the two species are strongly linked...”可知，当掠食动物总是吃掉大量的单一猎物时，这两种动物是紧密联系在一起的，故选C。
3．What will happen if the populations of top predators in a food web greatly decline？_D__ A．The prey species they directly attack will die out.
B．The species they indirectly attack will turn into top predators. C．The living environment of other species will remain unchanged. D．The populations of other species will experience unexpected changes.
解析：推理判断题。根据第三段中的small changes of top predators can lead to big effects throughout entire ecosystems以及其后举的例子可知，位于食物网顶端的掠食动物对其他物种的数量有着惊人的控制，即使是无直接联系的物种，故答案为D “其他物种的数量会发生意想不到的变化”。
4．What conclusion can be drawn from the examples in Paragraph 4？_A__ A．Uncontrolled human activities greatly upset ecosystems. B．Rapid economic development threatens animal habitats. C．Species of commercial value dominate other species. D．Industrial activities help keep food webs stable.
解析：段落大意题。第四段的第一句“And unplanned human activities have proved the idea of top－down control by top predators to be true.(未经计划的人类活动证明了顶端掠食动物自上而下控制的观点是正确的)”是这一段的主题句，下面的例子是为了证明它的，根据本段最后一句“这些行为已经大大影响了生态平衡”可知，人为的不受控制的行为会扰乱生态平衡，故答案为A。
5．How does an early－warning system help us maintain the ecological balance？_D__ A．By getting illegal practices under control. B．By stopping us from killing large predators.
C．By bringing the broken－down ecosystems back to normal. D．By signaling the urgent need for taking preventive action.
解析：推理判断题。由题干中的an early－warning system 定位到文章的最后一段。根据最后一段中的prevention is key可知，预防系统提前发出信号以让人们采取措施防止生态系统被破坏。
B
(2018·天津卷，B)
When I was 17，I read a magazine article about a museum called the McNay，once the home of a watercolorist named Marian McNay.She had requested the community to turn it into a museum upon her death.On a sunny Saturday，Sally and I drove over to the museum.She asked，“Do you have the address？”“No，but I'll recognize it，there was a picture in the magazine.”
“Oh，stop.There it is！”
The museum was free.We entered，excited.A group of people sitting in the hall stopped talking and stared at us.
“May I help you？” a man asked.“No，” I said.“We're fine.” Tour guides got on my nerves.What if they talked a long time about a painting you weren't that interested in？Sally had gone upstairs.The people in the hall seemed very nosy (爱窥探的)，keeping their eyes on me with curiosity.What was their problem？I saw some nice sculptures in one room.Suddenly I sensed a man standing behind me.“Where do you think you are？” he asked.I turned sharply.“The McNay Art Museum！” He smiled，shaking his head.“Sorry，the McNay is on New Braunfels Street.” “What's this place？” I asked，still confused.“Well，it's our home.”My heart jolted
(震颤)．I raced to the staircase and called out，“Sally！Come down immediately！”
“There's some really good stuff (艺术作品) up there.” She stepped down，looking confused.I pushed her toward the front door，waving at the family，saying，“Sorry，please forgive us，you have a really nice place.” Outside，when I told Sally what happened，she covered her mouth，laughing.She couldn't believe how long they let us look around without saying anything.
The real McNay was splendid，but we felt nervous the whole time we were there.Van Gogh，Picasso.This time，we stayed together，in case anything else unusual happened.
Thirty years later，a woman approached me in a public place.“Excuse me，did you ever enter a residence，long ago，thinking it was the McNay Museum？”
“Yes.But how do you know？We never told anyone.”
“That was my home.I was a teenager sitting in the hall.Before you came over，I never realized what a beautiful place I lived in.I never felt lucky before.You thought it was a museum.My feelings about my home changed after that.I've always wanted to thank you.”
文章大意：本文是一篇记叙文。如果你误把一户人家当成博物馆且四处参观，会是怎样一种奇特的经历呢？让我们读一下文章，看一看作者的亲身体验吧。
6．What do we know about Marian McNay？_A__ A．She was a painter.
B．She was a community leader. C．She was a museum director. D．She was a journalist.
解析：细节理解题。根据第一段中的watercolorist(水彩画家)以及下文“去博物馆看画”知，Marian McNay是一位painter (画家)，故答案为A。a community leader“社区领导”；a museum director“博物馆主管”；a journalist“记者”。
7．Why did the author refuse the help from the man in the house？_D__ A．She disliked people who were nosy. B．She felt nervous when talking to strangers. C．She knew more about art than the man. D．She mistook him for a tour guide.
解析：细节理解题。根据第四段中的“Tour guides got on my nerves.(导游令我烦扰)”知，“我”把那个人误认为是导游了，故答案为D。A项“她不喜欢爱窥探的人”，曲解文意；B项“与陌生人交谈时她感到紧张”，无中生有；C项“她比那个人更懂艺术”，无中生有。
8．How did the author feel about being stared at by the people in the hall？_A__ A．Puzzled. C．Frightened.
B．Concerned. D．Delighted.