选择知识点

It is often claimed that nuclear energy is something we cannot do without.We live in a consumer society,where there is a huge demand for commercial products of all kinds.Moreover,an increase in industrial production is considered to be one solution to the problem of mass unemployment.Such an increase needs an abundant and cheap energy supply.Many people believe that nuclear energy is endless and economical.There are a number of other advantages in the use of nuclear energy.Firstly,nuclear power,except for accidents,is clean.A further advantage is that a nuclear power station can be run by relatively few technical and managing staff.The nuclear power station represents a large step in our scientific research and,whatever the anti-nuclear group says,it is wrong to expect a return to more primitive sources of fuel.
However,those who disagree with nuclear energy point out that nuclear power stations bring a direct threat not only to the environment but also to the human race.Furthermore,it is doubtful whether finally nuclear power is a cheap source of energy.There have,for example,been very costly accidents in America and Russia.The possibility of increases in the cost of uranium and the cost to ensure its safety could price nuclear power out of the market.In the long run,environmentalists argue,nuclear energy may bring about the destruction of the human race.Thus,if we wish to survive,we cannot afford nuclear energy.Though nuclear energy programs are expanding,which assumes a continual growth in industrial production and consumer demands,it is doubtful whether this growth will or can continue.
Having weighed up the arguments on both sides,it seems there are good economic and environmental reasons for sources of energy other than nuclear power.



According to the passage,an increase in industrial production can ______ .

A. ensure the safety of nuclear power
B. overcome the resource crisis
C. solve the pollution problem
D. offer more working opportunities

According to the anti-nuclear group,nuclear energy has the following disadvantages EXCEPT that ______ .

A. it is a limited source of energy
B. it is harmful to the environment
C. it is a danger to the human race
D. it is an expensive source of energy

The writer's attitude toward nuclear energy is ______ .

A. indifferent
B. favorable
C. tolerant
D. negative

A city in Sweden has used rainbow-colored garbage recently.It has one of the most impressive recycling records in the world and met the EU's 2020 target of recycling 50% of waste many years ago.
Almost all the citizens in this city follow a strict recycling policy at home.People are expected to sort their household waste into seven separate categories,including food,textiles,cartons and metal.But what really makes the system stand out is the bright color code.
The significance for this becomes clear at the city's recycling factory.The bags are collected altogether,so when they arrive at the factory,they are mixed up.But thanks to those bright colors,scanners can select the bags and separate them easily.One of the benefits of this method of recycling is that there is less cross-pollution （交叉污染物），so more of the recycled waste can actually be used to make new things.The food waste in green bags is processed on site into mud to make biogas,which powers the city's buses.Waste that cannot be recycled is burned at a local factory to produce electricity.This creates greenhouse gases,reducing dependence on traditional fuels,such as coal.
As countries around the world try to improve their recycling degree,some may look up to this city as an example to follow - as long as they think they can persuade their citizens to get sorting work done properly at home.



What makes the system of rainbow-colored recycling so outstanding？ ______

A. The impressive colors of the rubbish bags.
B. The self-control of citizens.
C. The strict recycling policy.
D. The eco-friendly code.

Which of the following statements is true？ ______

A. Rainbow-colored rubbish is commonly seen around the world.
B. When the rubbish bags arrive at the plant,they are mixed up.
C. The food rubbish will not be recycled to make new things.
D. All rubbish is burned to create electricity.

If other countries want to recycle waste like this Swedish city,they first should ______ .

A. persuade citizens to use as much traditional fuel as possible
B. forbid citizens to create greenhouse gases
C. not allow citizens to create any waste
D. talk people into sorting household waste in a correct way

Where is this text most likely from？ ______

A. An announcement.
B. A poster.
C. A magazine.
D. A science fiction.

While elephants born without tusks（长牙）are not unheard they normally form just 2 to 6 percent of the population.However,that is not the case at Mozambique's Gorongosa National Park,where an astonishing 33 percent of female elephants born after the country's conflict ended in 1992 are tuskless.While that may appear to be just a coincidence,Joyce Poole,an elephant behavior expert,has another theory.The researcher thinks we may be witnessing unnatural evolution of the species due to the constant hunting of elephants for valuable ivory.
Poole says before the country's 15-year-long conflict,the park was home to over 4，000 elephants.However,by the time the conflict ended in 1992，about 90 percent of them had been killed for ivory to get money.Of the less than 400 survivors,over 50 percent of adult females had no tusks.Therefore,it is not surprising that the park's tuskless elephant population has grown greatly.
This is not the first time researchers have observed a great change in the population of elephants.At Zambia's South Luangwa National Park and Luangwa Game Management Area,areas which were heavily hunted in the 1970s and 1980s,35% of elephants 25 years old or older and 13% of those younger than 25 are now without tusks.A 2008 study published in the African Journal of Ecology found that the number of tuskless females at the Ruaha National Park in Tanzania went from 10.5 percent in 1969 to almost 40 percent in 1989，largely due to illegal hunting for ivory.
The recent ban on ivory in both the US and China should help get rid or a least reduce,elephant hunting.However,scientists are not sure how long it will lake for elephants with a higher rate of tuskless females,to change the trend.



What is the probable cause of the phenomenon mentioned in Paragraph 1？ ______

A. Illegal hunting.
B. Constant fanning.
C. A pure coincidence.
D. Natural evolution.

Why did people kill so many elephants during the conflict in Mozambique？ ______

A. To get money by selling ivory.
B. To develop new decorations.
C. To provide food for local people.
D. To make ivory products.

Which of the following had the earliest record on tuskless elephants？ ______

A. Gorongosa National Park.
B. South Luangwa National Park.
C. Ruaha National Park.
D. Lupande Game Management Area.

What does the underlined phrase "the trend" in the last paragraph refer to？ ______

A. Elephants facing greater danger.
B. Elephants growing more slowly.
C. Fewer female elephants staying alive.
D. More female elephants being tuskless.

Don't get close to the walls which______ .（　　）

Hopefully,all the students,_________ staying at home or living at school,are supposed to control themselves strictly.（　　）

The medical team ______ five doctors and eight nurses came back from Wuhan safely.（　　）

You should have asked for your parents' _______before you go out for a whole night.（　　）

Without his support, we wouldn't be______we are now.（　　）

How to Prevent Dehydration When the weather's warm,you need to make sure you drink enough water.But did you know that you lose your sense of thirst as you get older？This means you're more likely to become dehydrated,making you more prone to （有倾向） falls,heart disease,urinary-tract infections,kidney stones and confusion.A study from Loughborough University in the UK has shown that drivers who had only a little water an hour made twice as many mistakes as motorists who were properly hydrated.In fact,they made a similar number of errors to what you'd expect from someone over the drink-drive limit.
So how do you know when you're dehydrated？Warning signs include：
*Feeling tired
*Dry mouth and dry skin
*Dark urine
*Reduced appetite （食欲）
*Reduced concentration
*Headache
*Constipation.
But you might not notice any symptoms（症状）at all,so to make sure you stay hydrated：
*Keep a glass of water by your side when you're at home,and drink it regularly.
*Form a new drinking habit—for example,when watching TV，always reach for the water glass during an ad break.
*Take a small bottle of water with you when you go out.
*Always drink a large glass of water with a meal.
*Eat fruit and vegetables with high water content.
*Draw up a weekly water card—a bit like a coffee loyalty card—with a target of eight glasses.
of water a day.Mark it every time you have a glass of water.Award yourself a prize when it's full at the end of the week.
*Drink water before,during and after you take any exercise.



The word "dehydration" in the title may probably mean ______ .

A. loss of water from the body
B. confusion of the mind
C. warning signs of illnesses
D. a kind of weather sign

According to Paragraph 1，dehydration can ______ .

A. occur only in warm weather
B. make you get older and older
C. cause physical and mental problems
D. be easily noticed in our daily life

To make sure you stay hydrated,you'd better ______ .

A. take no notice of the warning signs
B. award yourself eight glasses of water
C. eat any fruit and vegetables you like
D. leave some water within your reach

The future of space exploration may depend on an art form from the past：origami （折纸艺术），the ancient art of paper folding.
Researchers from Washington State University（WSU），US，have used origami to possibly solve the problem of storing and moving fuel to rocket engines,a key challenge in space travel,according to Newswise.They've developed a foldable plastic fuel "bladder（囊状物）" resistant to super cold temperatures,which could be used to store and pump fuel in spacecrafts of the future.Their findings have recently been published in the journal Cryogenics.
"Folks have been trying to make bags for rocket fuel for a long time," said Jake Leachman,one of the lead researchers. "We currently don't do large,long-duration trips because we can't store fuel long enough in space."
Meanwhile,NASA is also looking to paper folding to help observe distant planets.The agency is currently developing Starshade,a foldable,sunflower-shaped piece of hardware that would help block starlight and enable telescopes to view distant objects more clearly in space.
"A huge part of my job is looking at something on paper and asking,'Can we fly this？'" Manan Arya,a technologist in California,said. "Once I realized this is how you fold spacecraft structures,I became interested in origami.I realized I was good at it and enjoyed it.Now,I fold constantly. "
Using origami for space purposes isn't new,however.Solar arrays（太阳能阵列），experimental wings for space shuttle programs and an inflatable（可充气的） satellite were also inspired by origami in both past and present space projects.
"With most origami,the magic comes from the folding," Robert Salazar,who helped design the Starshade and now works on the Transformers project,said in a statement. "There are so many patterns to still be explored."



How could the "bladder" help in future missions？ ______

A. To protect spacecrafts from extreme weather.
B. To help rocket engines cut energy consumption.
C. To be used to store and supply fuel in spacecrafts.
D. To be used to improve energy efficiency.

What can we know about NASA's Starshade？ ______

A. It can be used to get telescopes closer to stars.
B. It can help telescopes get clearer pictures of objects in space.
C. It can absorb a star's light before it enters telescopes.
D. It can enlarge the view of telescopes in space.

What is this text？ ______

A. A travel journal.
B. A science report.
C. A digest.
D. An advertisement.

Which can be the suitable title for the text？ ______

A. Folding into space.
B. The art of paper folding.
C. Space exploration.
D. The origami-inspired projects.