It is often difficult for farmers to identify diseases quickly enough to protect their crops and those on neighboring farms．Now，some farmers are using a simple device directly in the field to find viruses before they spread．
In Tanzania，several viruses are a threat to cassava crops．Farmers struggle to identify the diseases in an urgent effort to avoid severe crop damage．The disease identification process is often difficult when farmers are acting on their own．If they do not know what is attacking their crops，they cannot decide the best way to fight the disease．A device from British technology company Oxford Nanopore is changing that．The device extracts deoxyribonucleic acid，better known as DNA，from plants．DNA is the carrier of genetic information in nearly all living things．The device helps farmers identify what is harming their crops so they can change to more resistant crops．
Laura Boykin is with the University of Western Australia and also works with the Cassava Virus Action Project．She brought the device to a Tanzanian farm owned by Asha Mohamed．She said， "We are here collecting leaf punches from infected material to test，to do a DNA extraction and then start sequencing （排序） in the field．" The testing identified a number of viruses in the cassava fields near Mohamed's farm．The process also discovered that plants considered resistant to disease had a very low viral level．Once the viruses were identified，Asha Mohamed was given two kinds of seeds that are resistant to the diseases．
In another case，DNA was collected from a pawpaw tree farm in Kenya．With that test，the technology was able to identify diseases affecting Naomi Mumo's crops．Naomi Mumo said， "All my pawpaw were affected by a disease，and I didn't know what kind of disease it was．But now，I have people who have identified the disease using new technology，and within a very short time．So I'm very happy．"
The speed at which farmers identify diseases can mean the difference between the success or failure on large areas of crop land．Now，the use of such simple and easily transportable DNA sequencing devices is making that possible．
（1）What's the main idea of the whole passage？CC
A．Farmers In Tanzania struggle to identify the diseases in their crops
B．How Laura Boykin helped Asha Mohamed to identify the viruses．
C．DNA sequencing device helps farmers to find viruses and identify the diseases in their crops quickly．
D．A DNA sequencing device helps farmers to identify the diseases and keep healthy．
（2）Which of the following best explains "extracts" underlined in paragraph 2？DD
A．produces
B．creates
C．refuses
D．gets
（3）We can infer from the passage that Naomi Mumo isBB with the DNA sequencing device．
A．relaxed
B．satisfied
C．disappointed
D．a(chǎn)nnoyed
（4）Which of the following is not true according to the passage？CC
A．Farmers often have difficulty in identifying diseases in their crops quickly by themselves．
B．DNA carries genetic information in nearly all living things．
C．Both Asha Mohamed and Naomi Mumo are farmers in Tanzania．
D．If farmers can identify diseases in their crops quickly，they can protect their crops and succeed on large areas of crop land．
【考點(diǎn)】說(shuō)明文．
【答案】C；D；B；C
【解答】
【點(diǎn)評(píng)】
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發(fā)布：2024/7/5 8:0:9組卷：9引用：4難度：0.8
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(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．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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