Fishing is a popular activity and every fisherman knows the rule: Keep the big ones, throw the smaller ones back. The idea behind Lt is simple - the larger fish are probably older. If you keep the smaller ones, they won’t be able to reproduce, and the fish population is in danger.
But fishing out the largest fish from a population has an unwanted effect: Over time, fewer adult fish get really big. If only the smaller fish reproduce(繁殖), then future generations become smaller. This is an example of evolution(進(jìn)化) in action.
One scientist, Dr David Conover has spent the last decade studying the effects of the “keep the big ones” rule and if they can be reversed(顛倒).
To set up his experiment, Conover and his team caught hundreds of silverside fish and divided them into six groups. For two groups, Conover followed the “keep the large ones” rule and took out the biggest fish. For two other groups, he removed only the small fish.
For the last two groups, he removed fish at random (隨意的).
After five years, he measured the fish in each group. In the two groups where the largest fish were regularly removed, the average fish size was smaller than the average size in the other groups. Here was evolution in action: If only small fish survive to reproduce, then future generations of fish will also tend to be small.
For the second five years of his experiment, Conover changed the rules and took fish randomly from each group. At the end of the experiment, he found that the fish that were in the “keep the large ones” group for the first five years had started to get larger again, although he calculated it would take at least 12 years for the fish in that group to return to their original size.
In other words, it takes less time to shrink(變小) than it does to recover.
小題1: The underlined word “it” (Line 2) refers to “           ”
A.the activityB.the fish
C.the ruleD.the fisherman
小題2:Why do many people follow the “keep the big ones, throw the small ones back” rule?
A.It helps to protect fish numbers.
B.It helps to protect fish size.
C.It is the custom in most countries.
D.They will be punished if they don’t.
小題3:What did Conover find after the first five years of his experiment?
A.The “keep the big ones” rule made no difference to fish size.
B.The “keep the big ones” rule made fish smaller on average.
C.The “keep the big ones” rule made the fish bigger on average.
D.The “keep the big ones” rule affected all fish populations in the same way.
小題4: What is the author’s intention in writing this article?
A.To encourage people to fish more carefully.
B.To urge governments to change the rules of fishing.
C.To describe the results of a scientific experiment.
D.To introduce the rules of fishing to readers.

小題1:C
小題2:A
小題3:B
小題4:C

試題分析:這篇短文主要通過實(shí)驗(yàn)的方式驗(yàn)證是否可以顛覆“抓大放小”的釣魚潛規(guī)則,以利于魚的數(shù)量的穩(wěn)定。
小題1:細(xì)節(jié)理解題。根據(jù)短文every fisherman knows the rule: Keep the big ones, throw the smaller ones back.的描述可知,這里指的是“抓大放小”的規(guī)則。故選C。
小題2:細(xì)節(jié)理解題。根據(jù)短文第一段 If you keep the smaller ones, they won’t be able to reproduce, and the fish population is in danger的描述可知,“抓大放小”的規(guī)則有利于保護(hù)雨的數(shù)量。故選A。
小題3:細(xì)節(jié)理解題。根據(jù)短文第六段 In the two groups where the largest fish were regularly removed, the average fish size was smaller than the average size in the other groups的描述可知,“抓大放小”的規(guī)則讓魚總體變小。故選B。
小題4:主旨大意題。文章主要通過實(shí)驗(yàn)的方式驗(yàn)證是否可以顛覆“抓大放小”的釣魚潛規(guī)則,描述科學(xué)實(shí)驗(yàn)的結(jié)果。故選C。
練習(xí)冊(cè)系列答案
相關(guān)習(xí)題

科目:初中英語 來源:不詳 題型:閱讀理解

Can you imagine living in the desert for a whole year, watching the activities of a group of busy ants? Deborah Gordon did exactly that. She finally found out that there were four main groups of workers in the ant team: cleaners, haulers(搬運(yùn)工), gatherers and security (安全) ants. Each group did their own job to finish the task of the whole team.
Cleaner ants carried waste food from inside the nest to outside. Hauler ants walked on the top of the nest and cleared rubbish. Gatherer ants went out to find food for the whole team and security ants fought against anyone who wanted to hurt the members of the team.
While she was watching the ants in the desert, Deborah found that the most interesting part was watching the ants dealing with difficulties, such as fighting against other insects that wanted to destroy their nest, or a big fire. At those moments, they would all stop what they were doing and go to help security ants to protect their home.
What do we do when people around us meet difficulties? What have we done to turn our world into a better place? It’s time to think.
小題1: If there was a fire near their home, the groups of ants would________.
A.just do their own job
B.run away at once
C.help to fight against the fire
D.go back into their nest
小題2:Which of the following is TRUE according to the passage?
A.Cleaner ants carried waste food from outside the nest to the inside.
B.Gatherer ants went out to find food for themselves.
C.Each group did their own job when meeting difficulties.
D.There were some other insects that wanted to destroy their nest.
小題3:The writer mainly wants to tell us____________.
A.everyone should help others when they meet difficulties
B.there were four groups of workers in the ant team
C.how Deborah Gordon lived in the desert
D.Deborah Gordon is a brave woman

查看答案和解析>>

科目:初中英語 來源:不詳 題型:完形填空

閱讀表達(dá)。(共5小題,計(jì)5分)
閱讀短文,根據(jù)要求完成下面各小題。
★8-year-old boy becomes a CEO
Harli Jordean, an 8-year-old boy from Stoke Newington, London loves marbles(彈珠)very much. With his mother’s help, he set up his own website named marblelcing.co.uk. He sells all kinds of marbles online and his online store is very popular. Harli’s dream is to become the owner of one of the biggest toy stores in the world.
★Matt Cardle-from an unknown(不知名的)painter to a hot singer
Matt Cardle, a 27-year-old young man from a small town in England liked music very much, but he had to do different jobs to make a living. He worked as a postman, milkman and a painter. Life was not easy, but Matt__(1)_________________________(從沒有放棄過他的夢(mèng)想)-to be a singer. In 2010, he took part in a famous British singing talent show(歌唱真人秀)and won first place.
★_________(2)__________________________
The Zapps are from Argentina. With the help of their old 1928 car, they began their tour on January 23, 2000. In ten years, they traveled to over 40 countries with their four children. When people asked what made them travel the whole world, they answered, “It’s just one dream, a big one, from Argentina to the whole world.”
Truly, all of us have dreams.(3) Each one of us can make our dreams come true if we start it now!
小題1:What does Hark Jordean dream of doing?
_________________________________________________________________
小題2:Translate the sentence underlined into English.
Matt _____________________________________________________________
小題3:What kinds of jobs did Matt Cardle do before he became a hot singer?
                                                                 
小題4:請(qǐng)把短文中劃線的句子?譯成漢語。
__________________________________________________________________
小題5:請(qǐng)給?處第三則新聞擬一個(gè)恰當(dāng)?shù)挠⑽臉?biāo)題
__________________________________________________________________

查看答案和解析>>

科目:初中英語 來源:不詳 題型:完形填空

Respect your teachers.
First of all, students should respect the teachers. You should      your teachers in the classes. That means to give your respect to him, to stand from your chairs when the teacher enters the classroom, etc. Attend any class attentively. In class of a certain subject or a teacher you don’t like very much, if it is totally anarchy(無政府狀態(tài)), how can we talk about respect?
Play by the     .
If your teacher wants you to take notes in class, do it. If she tells you to sharpen your pencils only before class starts, listen to her. If she     late homework, do yours on time. Sometimes classroom rules seem strict or even silly, but most teachers know what’s necessary to make things run well and what it takes to let the learning begin. And the better the learning environment, the      you will be!
Expect him/her to like you.
Teachers are teachers because they like kids. Given the chance, most teachers want to be your    , too. Respect your teacher, but do not be afraid of him/her. He/ she wants you to have a great school year just as much as you want to have one!
Put first things first.
Friends are a fun part of school. But they are not the most important part. When your teacher is teaching, give him/her full attention,      when it’s hard to do. Class will end and the ten-minute break will come soon enough, and that’s the time for playing with your friends
小題1:
A.pay attention toB.play withC.live on D.pick up
小題2:
A.chancesB.timesC.rulesD.classes
小題3:
A.hopesB.refusesC.wantsD.a(chǎn)sks
小題4:
A.moreB.biggerC.harder D.smarter
小題5:
A.leader B.friendC.brother D.classmate
小題6:
A.evenB.stillC.beforeD.a(chǎn)s

查看答案和解析>>

科目:初中英語 來源:不詳 題型:閱讀理解

 Scientists have made the world’s first human-sheep----with the body of a sheep and half-human organs(器官). Amazing, but true. The sheep is15percent human and 85 percent sheep. The breakthrough(突破)makes it possible to use animal organs in human bodies in the future. Professor Esmail Zanjani of University of Nevada, US, has spent seven years And over $9 million on the work. Zanjani took stem cells(干細(xì)跑) from the human body and put them into the sheep while it was still in its mother’s body. The stem cells made other cells that grew into organs. Zanjani believe that in the future such sheep might be used to help humans. Two months later a human-sheep is born, it has a liver(肝臟), heart, ling(肺) and brain that are part-human. These organs could be used to help people in need of them. There are different opinions about his work, however. Some say that scientists don’t have the right to create new creature(生物). Using animal organ might bring animal viruses(病毒) into human bodies. Others are afraid that the work might change sheep. But Professor Anjani has said that this is impossible.
小題1: According to the passage, we know that the first human-sheep looks like________.
A.a(chǎn) sheepB.a(chǎn) goat
C.a(chǎn) catD.a(chǎn)n elephant
小題2: The appearance(出現(xiàn)) of the first human-sheep means_________.
A.sheep will be cleverer and stronger in the future
B.sheep are as important as human in the future
C.sheep will take the place of humans in the future
D.a(chǎn)nimal organs may be used in human bodies
小題3:Some people think it’s not good to use animal organs because they’re afraid that _____
A.humans will change into animals
B.There will be fewer and fewer animals in the future
C.the organs may bring animal viruses into human bodies
D.many animals will be dead after they give their organs to humans
小題4:. Zanjani put some stem cell from the human body and put them into the sheep while it was still in its mother’s body. He “____________” .
A.created a new stem cellB.created a new creature
C.created a new organD.created a new food
小題5: According to the passage, “__________” is not true.
A.The world’s first human-sheep is 15% percent human and 85% sheep
B.The world’s first human-sheep has many organs that are part-human
C.Zanjani created the world’s first human-sheep to make the sheep grows faster
D.The world’s first human-sheep is a sheep with the body of a sheep and half-human organs.

查看答案和解析>>

科目:初中英語 來源:不詳 題型:閱讀理解

The air plant has wonderful and amazing features. It takes in moisture(水汽)from the air through its leaves.Although it is seen growing on another object or plant to support itself.
To prevent the roots from being too wet,avoid(避免) planting it in soil. Keep the roots in a well—ventilated(通風(fēng)良好的)environment. Air plants can grow well hanging from fishing lines. They can also be hung from seashells, teacups or even on wood.
Water the air plant once in a while. Simply let the water fall from the roots. The roots will take in the water for the air plant. The air plant can live between 0℃° and 51 ℃. It does not need to be in the light all the time. However, sunlight(morning and evening only)helps it to reproduce(繁殖)faster. When it flowers,it turns a colorful pink, red or orange.At most 8 young plants can grow from the air plant.When these grow to half the size of the parent plant, simply pull them away gently from the parent plant and plant them in another place.
The lifespan of an air plant depends on the care it gets and the environment it is placed in. Generally, all air plant can live for many years.
Because they are so beautiful and easy to take care of, air plants are excellent as birthday gifts or housewarming gifts.
小題1:The air plant takes in moisture from ______.
A.other plantsB.the air
C.the rootsD.other objects
小題2: An air plant must NOT be placed in _______.
A.soilB.seashells
C.teacupsD.wood
小題3:Morning sunlight can help the air plant _________.
A.become drier
B.produce young plants faster
C.turn into different colors
D.become half the size of the parent plant
小題4: The underlined word “depend on” most probably means _______.
A.支持B.繼續(xù)
C.取決于D.應(yīng)付
小題5: The air plant is easy to take care of because it ______.
A.is a famous plantB.needs little water and sunlight
C.grows on other plants and objectsD.makes the garden beautiful

查看答案和解析>>

科目:初中英語 來源:不詳 題型:完形填空

根據(jù)短文內(nèi)容,從 A、B、C、D 四個(gè)選項(xiàng)中選出一個(gè)能填入相應(yīng)空格內(nèi)的最佳答案,并把答題卡上對(duì)應(yīng)題目的答案標(biāo)號(hào)涂黑。
It is two months since MH730 first went missing in the early hours of March 8th, while flying from Kuala Lumpur to Beijing. Malaysia Airlines said it was terribly sorry that MH370 ended in the southern Indian Ocean. People are losing hope that the passengers on the      could return alive and realize they should know how to save themselves when accidents like this happen in the air.
  1985, an Australia professor, Ed Galea, has interviewed 2,000 survivors of 105 airplane accidents, searching for the keys to survival (n.幸存) and found out      golden rules after years of research.
First, make sure that the airline does not keep your family members too far away on the plane, if you are traveling in family group.     ? It’s natural that while feeling in danger, you’ll probably want to meet the family before you can calmly move out.
Second, how do you untie (解開) your seat belt on a plane? By lifting a latch.            you can’t untie your seat belt, you can hardly run away and your chances of survival will drop.
Third, the           to the exits (逃生口), the more likely you are to survive. Count exactly how many rows you are from the nearest two exits. Why two exits? Because this helps you find at least               even in the sudden dark during an accident.
Fourth, we would be safer if airline seats faced backward, according to Galea’s research. But the problem is that most of the passengers              traveling with their back facing the direction of travel.
Fifth, “Smoke is dangerous to your health. If you take in too much of it, your will die,” explains Galea. You must learn how to use a smoke mask. Without the knowledge of putting on a mask, you’ll              time trying to put it on—time that could be used to run away.
At last, listen to the flight attendants before flying and look      at everything shown on a video or a safety card. Always be prepared. Good luck to you.
小題1:
A.trainB.planeC.busD.ship
小題2:
A.InB.FromC.SinceD.On
小題3:
A.fourB.fiveC.sixD.seven
小題4:
A.WhoB.HowC.WhenD.Why
小題5:
A.UnlessB.IfC.UntilD.After
小題6:
A.closeB.closerC.farD.farther
小題7:
A.a(chǎn)llB.themC.oneD.both
小題8:
A.don’t likeB.enjoyC.hopeD.don’t want
小題9:
A.saveB.haveC.wasteD.enjoy
小題10:
A.carefulB.carefullyC.carelessD.carelessly

查看答案和解析>>

科目:初中英語 來源:不詳 題型:閱讀理解

A 15-year-old student who invented a flashlight(手電筒) getting power from the holder's body heat is going home today from California with a big prize and a chance to do further research.
Ann Makosinski was the only Canadian among the four winners at Google's international science competition. Thousands of young scientists from around the world took part in the competition.
Winning the science and technology competition was "a surprise". Ann said, "I think it will have a great influence on my future."
Ann thanked her family for encouraging her interest in science and said that her first toy was a box of transistors(晶體管).
Ann's prize includes $ 25,000 and a "once in a-lifetime expericnce" from Google for her Hollow Flashlight, which has no moving parts or batteries.
The idea for the invention came from seeing unwanted batteries and her friend's experience. When Ann visited a friend in the Philippines, she saw the friend couldn't study when it became dark because there was no electricity or light. She saw the need for a flashlight that has no batteries - Hollow Flashlight.
In her project, Ann wrote "I made two flashlights that do not use any batteries or harmful materials. They do not create any noise and will always work. The flashlight needs at least a 5℃ temperature difference between the holder's body and the environment around to produce light."
A video of Ann explaining how she creatcd the flashlight has been watched more than 1.4 million times on the Internet.
Though Ann was successful, she has not made a decision about her career path. Ann hopes that she can find a way to join her love of film and science together.
The four winners were chosen from 15 final competitors from eight countries. The competition attracted thousands of students in 120 countries.

小題1:In which part of a newspaper can we probably read this passage?
A.Travel.B.Culture.C.Technology. D.Advertisement.
小題2: The first paragraph is written to be a(n) ________.
A.introduction B.warningC.a(chǎn)rgumentD.discussion
小題3:Paragraph 6 mainly tells us ________.
A.what Ann saw in the PhilippinesB.why Ann invented Hollow Flashlight
C.how Ann's family encouraged her interestD.what prize Ann got for Hollow Flashlight
小題4:According to the passage, we learn ________.
A.easy to win the international science competition
B.Hollow Flashlight is safe, noiseless and can save energy
C.Ann has made a decision to be a scientist in the future
D.few people are interested in how Ann created the flashlight

查看答案和解析>>

科目:初中英語 來源:不詳 題型:閱讀理解

Decisions, decisions! Our lives are full of them, from the small ones to the life-changing. The right to choose is central to everyone. Yet sometimes we make bad decisions that leave us unhappy or full of regret. Can science help?
Most of us know little about the mental processes that lie behind our decisions. Luckily, what psychologists(心理學(xué)家)are finding may help us all make better choices. Here are some of their amazing discoveries to help you make up your mind.
Consider your emotions. You might think that emotions are the enemy of decision making, but in fact they are a part of it. Whenever you make up your mind, your brain’s emotional centre is active. University of Southern California scientist, Antonio Damasia, has studied people with damage to only the emotional parts of their brains , and found that they were unable to make basic choices about what to wear or eat. Damasia thinks this may be because our brains store emotional memories of past choice, which we use to help the present decision-making.
However, making choices under the influence of an emotion can greatly affect the result. Take anger, for example. A study by Nitika Garg of the University of Mississippi and other scientists found the angry shoppers were more likely to choose the first thing they were offered rather than considering other choices. It seems that anger can lead us to make quick decisions without much thinking.
All emotions affect our thinking and motivation(動(dòng)機(jī)),so it may be best to avoid making important decisions under their influence. Yet strangely there is one emotion that seems to help us make good choices. The American researchers found that sad people took time to consider the various choices on offer, and ended up making the best choices. In fact many studies show that people who feel unhappy have the most reasonable view of the world.
小題1:According to the text, what may help us make better decisions?
A.To think about happy times.
B.To make many decisions at a time.
C.To stop feeling regretful about the past.
D.To learn about the process of decision-making.
小題2:What does the underlined word “central” mean?
A.中心的B.中央的C.起決定作用的D.后悔的
小題3:Damasia’s study suggests that ________.
A.emotions are the enemy of decision making.
B.our brain has nothing to do with decision making.
C.people with physical damage find it hard to make up their minds.
D.our emotional memories of past choices can affect present decisions.
小題4:Why are angry shoppers more likely to choose the first thing they are offered?
A.They often forget their past choices.
B.They make decisions without much thinking.
C.They tend to save time when shopping.
D.They are too angry to bargain.
小題5:What do we learn from the text?
A.Emotions are a part of decision-making.
B.Sad people always make worse choices.
C.No emotion seems to help us make good choices.
D.Only sad feeling affect our thinking and motivation.

查看答案和解析>>

同步練習(xí)冊(cè)答案