Have you ever noticed that some people can eat what they want and stay in shape，while others carefully watch what they eat and still put on weight？How annoying!However，scientists are beginning to believe that some people get the ability to stay thin from their parents.
Scientists say that when some people eat，their bodies will naturally store the excess energy from food as fat.These people gain weight if they eat more than they need each day.Meanwhile，other people eat more than they need but their bodies are able to "burn off" the extra food without making fat，so they rarely have weight problems.
To show that this is true，scientists have experimented on laboratory mice.They gave the mice a special diet with a lot of fat.Some mice gained weight while the other mice stayed thin，even though both groups of mice ate the same amount of food and got the same amount of exercise.Scientists concluded that weight gain seemed to be influenced by genetic （基因的） factors.They also believe they have now identified the genes that may cause this tendency.These genes，according to the scientists，get passed down the generations.Armed with this knowledge，they believe it may be possible to develop medicines that can target the genes and stop people from gaining weight.
The study of weight gain is becoming more important as the numbers of people who are overweight continues to grow.In the United States，over seventy percent of the population have weight problems.This means they are at risk of illness such as high blood pressure and heart disease.
Current medicines for weight control do not work very well because they can have serious side effects，such as heart problems.However，it takes a long time to develop and thoroughly test new drugs.Therefore，despite this breakthrough in the study of weight-loss drugs，scientists and health professionals all agree that currently the best way to control weight gain is to have a healthy，balanced diet and an active lifestyle with daily exercise.This will not only help people avoid becoming overweight，but also help them stay healthy and energetic.
（1）According to the scientists，some people AA.
A．a(chǎn)re able to stay thin because of genetic factors
B．can eat what they want and stay healthy forever
C．usually keep doing exercise to lose their weight
D．don't eat anything every day but still put on weight
（2）Some people don't need to worry about weight problems because DD.
A．they eat many vegetables
B．they eat less than others
C．they don't store any energy from food as fat
D．they can burn off the extra food without making fat
（3）What can we learn from the passage？ BB
A．Fewer people will have weight problems in the future.
B．People with weight problems may suffer from heart trouble.
C．We now have good medicine for people with weight problems.
D．The result of the experiments on mice and humans are different.
（4）What does the last paragraph imply？ BB
A．Current medicine solve weight problems well.
B．We should exercise regularly and eat properly.
C．Taking exercise every day may cause heart problems.
D．Testing new drugs is hard because of the side effects.
【考點(diǎn)】說明文．
【答案】A；D；B；B
【解答】
【點(diǎn)評(píng)】
聲明：本試題解析著作權(quán)屬菁優(yōu)網(wǎng)所有，未經(jīng)書面同意，不得復(fù)制發(fā)布。
發(fā)布：2024/5/27 14:0:0組卷：14引用：4難度：0.5
相似題
-
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(shí)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．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 -
3．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
把好題分享給你的好友吧~~