More than 30%of the world's population lives in drylands,areas that experience significant water shortages.Engineers and scientists at the University of Texas at Austin have developed a unique solution to help people in these areas access clean drinking water.
They developed a low-cost gel film(凝膠膜)that can pull water from the air in even the driest climate.Combining two simple ingredients,cellulose and konjac gum(魔芋膠),the gel is inexpensive to produce.Just one kilogram of gel can absorb up to six liters of water in a dry climate.For those living in a climate with relative humidity(潮濕),one kilogram of gel can collect up to 13 liters of water a day.As the gel is so inexpensive and easy to make,it may offer a way of providing drinking water to countries with water shortages.
Previously,researchers have harvested fresh water from fog and dew,but that only serves areas with high humidity.Other attempts at pulling water from desert air are typically energy-intensive and do not produce much.In fact,this gel is a vast improvement from previous water harvesting technologies.The maximum water harvested has been 5.87 liters in places with relative humidity.This new gel doubles this amount,uses no energy and is simple to operate and it can be molded into a shape or size that best suits the user.
"This new work is about practical solutions that people can use to get water in the hottest,driest places on Earth,"said Guihua Yu,professor at the Cockrell School of Engineering."This could allow millions of people without consistent access to drinking water to have simple,water generating devices at home that they can easily operate."
"This is not something you need an advanced degree to use,"the paper's lead author,Youhong "Nancy"Guo said."It's straightforward enough that anyone can make it at home if they have the materials."Scientists are planning on making a thicker gel that will increase the yield,making this technology a practicable solution to drought.
(1)What do we know about the gel film from paragraph 2?BB
A.It can increase the humidity of the air.
B.It can harvest drinking water from the air.
C.It has been widely applied in desert areas.
D.It's quite energy-consuming to produce the gel.
(2)Why does the author mention previous water harvesting methods in paragraph 3?AA
A.To introduce the advantages of the new gel.
B.To state the tough living conditions in dry regions.
C.To show the process of manufacturing the new gel.
D.To present the theory of water harvesting technologies.
(3)What is Guihua Yu's attitude towards the new water-harvesting method?CC
A.Skeptical.
B.Indifferent.
C.Hopeful.
D.Disapproving.
(4)What are the scientists planning to do next?AA
A.Developing a thicker gel.
B.Teaching people to make the gel.
C.Producing the gel on a large scale.
D.Raising money for further research.
【答案】B;A;C;A
【解答】
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發(fā)布:2024/4/20 14:35:0組卷:2引用:3難度:0.5
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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.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.
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C.Able to make corrections.
D.Active in planting trees.
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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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(1)Why did the author conduct the experiment?
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C.To prove sensitivity of Sandy's nose.
D.To teach Sandy to tell different smells.
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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.
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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
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