People diet to look more attractive．Fish diet to avoid being beaten up，thrown out of their social group，and getting eaten as a result．That is the fascinating conclusion of the latest research into fish behavior by a team of Australian scientists．
The research team have discovered that subordinate fish voluntarily diet to avoid challenging their larger competitors． "In studying gobies we noticed that only the largest two individuals，a male and female ，had breeding（繁殖） rights within the group， "explains Marian Wong． "All other group members are non-breeding females，each being 5～10% smaller than its next largest competitor．We wanted to find out how they maintain this precise size separation．"
The reason for the size difference was easy to see．Once a subordinate fish grows to within 5-10% of the size of its larger competitor，it causes a fight which usually ends in the smaller goby being driven away from the group．More often than not， the evicted fish is then eaten up．
It appeared that the smaller fish were keeping themselves small in order to avoid challenging the boss fish．Whether they did so voluntarily，by restraining how much they ate，was not clear．The research team decided to do an experiment．They tried to fatten up some of the subordinate gobies to see what happened．To their surprise，the gobies simply refused the extra food they were offered，clearly preferring to remain small and avoid fights，over having a feast．
The discovery challenges the traditional scientific view of how boss individuals keep their position in a group．Previously it was thought that large individuals simply used their weight and size to threaten their subordinates and take more of the food for themselves，so keeping their competitors small．
While the habits of gobies may seem a little mysterious，Dr．Wong explains that understanding the relationships between boss and subordinate animals is important to understanding how hierarchical （等級的） societies remain stable．
The research has proved the fact that voluntary dieting is a habit far from exclusive to humans． "As yet，we lack a complete understanding of how widespread the voluntary reduction of food intake is in nature，" the researchers comment． "Data on human dieting suggests that，while humans generally diet to improve health or increase attractiveness，rarely does it improve longterm health and males regularly prefer females that are fatter than the females' own ideal．"
（1）When a goby grows to within 5-10% of the size of its larger competitor，it AA．
A．faces danger
B．has breeding rights
C．eats its competitor
D．leaves the group itself
（2）The underlined words "the evicted fish" in Paragraph 3 refer to DD．
A．the fish beaten up
B．the fish found out
C．the fish fattened up
D．the fish driven away
（3）The experiment showed that the smaller fish BB．
A．fought over a feast
B．went on diet willingly
C．preferred some extra food
D．challenged the boss fish
（4）What is the text mainly about？ DD
A．Fish dieting and human dieting．
B．Dieting and health．
C．Human dieting．
D．Fish dieting．
【答案】A；D；B；D
【解答】
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發(fā)布：2024/5/27 14:0:0組卷：17引用：2難度：0.5
相似題
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1．If you see a group of people dancing and singing on the street or in the railway station，you don't need to feel surprised.They are a flash mob（快閃族），which is a group of people who come together suddenly in a public place，do something unusual for a brief period of time，and then quickly break up.They are usually organized with the help of the Internet or other digital communication network.
At a predetermined time，they gather and perform some distractions（消遣）such as waving their hands and exchanging books.Then，they quickly break up before the police can arrive.Using mobile phones the flash mob can change its location if the first one has been replaced for any reason.
Bill Lasik，senior editor of Harper's Magazine，organized the first flash mob in Manhattan in May 2003 and the first successful flash mob came together on June 3，2003--after the first attempt was foiled at Macy's department store.Lasik claimed that the activity was designed to make fun of hipsters（時髦的人），and call attention to the cultural atmosphere.
Flash mob gatherings can sometimes shock people.Such an activity might seem amusing and untrue，but it also might frighten people who are not aware of what is taking place.Undoubtedly，flash mobs can serve as good political tools in any direction.They also have great economic potential，such as using flash mobs to advertise a product.
The flash mob is now becoming more and more popular.People use it to do many things.For example，in 2009，Michael Jackson's fans took part in a flash mob to remember him.Hundreds of his fans gathered singing and dancing Michael's famous song Beat It together.Flash mobs give people from all walks of life an opportunity to come together to create a memory.
（1）The underlined word "foiled" in Paragraph 2 can be replaced by "".
A．forgotten
B．prevented
C．a(chǎn)nnounced
D．confirmed
（2）What can you learn about the flash mob from the passage？
A．The flash mob usually breaks up quickly for lacking enough time.
B．Once the place for the activity is determined，it can't be changed.
C．The flash mob can be made use of in many fields for fun.
D．It gives people the chance to come together to do something unusual.
（3）The main purpose of the passage is to.
A．entertain
B．encourage
C．inform
D．persuade
（4）The writers attitude towards the flash mob is.
A．negative
B．objective
C．favorable
D．doubtful發(fā)布：2024/12/20 8:0:13組卷：17引用：2難度：0.5 -
2．Our dog Sandy is a golden retriever（尋回犬）.Once we performed an experiment to see how keen his nose was.There was one particular pile that must have had hundreds of sticks.We picked up one stick carved an X on it，walked away from the pile and then threw it back into the pile，not once but a dozen times into the pile.It was impossible for us to tell with any certainty which slick we had originally chosen.Each time he brought back that stick，It wasn't the shape or the size or the look of the stick that he used to pick it out from all the others.It was the smell we left on the stick.It is hard to imagine，hut for dogs every living creature has its own distinctive smell.
The noses of people have about 5 million cells that sense smell.Dogs' noses have anywhere from 125 to 300 million cells.Moreover，these cells are closer to the surface than cells in our noses，and more active.It has been estimated that dogs such as Sandy have noses that are a million times more sensitive than ours.Clothes that we haven't worn for weeks，and places we've only touched lightly indicate our presence to dogs.
His ears are also remarkable.He can hear sounds that humans can't and at distances which are astonishing.It is over our head to know and understand that world.Yet we have the advantage of being able to imagine what his experience is like，though he probably doesn't think too much about how we see the world.
The environment is the world that all living things share.Living creatures are born into the environment and are part of it.Yet there is no creature who perceives（感知到）all of what is and what happens.For a dog like Sandy a book isn't much different than a stick，whereas for us one stick is pretty much like every other stick.There is no one world experienced by all living creatures.
（1）Why did the author conduct the experiment？
A．To train Sandy to pick out sticks.
B．To show how fast Sandy found sticks.
C．To prove sensitivity of Sandy's nose.
D．To teach Sandy to tell different smells.
（2）What does the author intend to do in paragraph 2？
A．Support the conclusion with numbers.
B．Summarize the previous paragraph.
C．Provide some advice for the readers.
D．Introduce a new topic for discussion.
（3）What does the underlined idiom in paragraph 3 mean？
A．Amazing.
B．Difficult.
C．Reasonable.
D．Inconvenient.
（4）Which of the following best expresses the authors opinion in the last paragraph？
A．Worlds to experience.
B．An environment to share.
C．No environment，no creatures.
D．One environment，many worlds.發(fā)布：2024/12/18 14:30:1組卷：5引用：2難度：0.5 -
3．The world is a greener place than it was 20 years ago．Recent NASA satellites data（2000-2017）have shown that human activities in China and India dominate this greening of the planet，thanks to ambitious tree-planting programmes in China and intensive agriculture in both countries．
The researchers from Boston University found that global green leaf area has increased by 5 percent in the new century，an area equal to all of the Amazon rainforest．China alone accounts for 25% of the global net increase in leaf area with only 6.6% of global vegetated area．China's contribution comes in large part from its programmes to conserve and expand forests，taking up about 42 percent of the greening．The greening from farmlands in China is about 32%，but that in India is about 82%．
Rama Nemani，a research scientist at NASA's Ames Research Centre and a co-author of the study said， "When the greening of the Earth was first observed，we thought it was due to a warmer，wetter climate and fertilization from the added carbon dioxide in the atmosphere．But with data from NASA satellites，scientists realized that humans are also contributing，which was all against our expectations．"
Nemani sees a positive message in the new findings． "Once people realize there is a problem，they tend to fix it，" he said． "In the 1970s and 1980s in India and China，the situation around vegetation loss was not good．In the 1990s，people realized it，and today things have improved．Humans are incredibly resilient．That is what we see in the satellite data．"
However，the researchers rang bells as well．They said that the gain in global greenness did not necessarily make up for the loss of natural vegetation in regions like Brazil and Indonesia．
（1）What is the second paragraph mainly about？
A．The decreasing size of the Amazon rainforest．
B．China's bigger contribution to global greening．
C．Total global green leaf area in the new century．
D．China's programmes to conserve and expand forests．
（2）What surprised scientists regarding global greening？
A．Human activities．
B．Suitable for analyzing data．
C．A warmer and wetter climate．
D．Carbon dioxide in the atmosphere．
（3）What does the underlined word "resilient" probably mean？
A．Good at making programmes．
B．Suitable for analyzing data．
C．Able to make corrections．
D．Active in planting trees．
（4）What does the last paragraph imply？
A．It is urgent to protect global natural resources．
B．Much remains to be done for global greenness．
C．Brazil and Indonesia lose most of their vegetation．
D．Global greenness needs all countries to work together．發(fā)布：2024/12/20 5:0:3組卷：7引用：1難度：0.6
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