3 . On paper, hydrogen（H2）looks like a dream fuel. Coal, oil, and natural gas produce carbon dioxide, which warms the earth when burned, Hydrogen produces pure water. Hydrogen packs more energy into less space than a battery（but certainly less than petrol）. Also, empty tanks（燃料箱）can be refilled with hydrogen much faster than refilling empty batteries with electricity.

While in practice, things are trickier. Storing a meaningful amount of hydrogen gas requires pressing it several hundred-fold. Changing it into the liquid form is another option, but it should be cooled to-253C. Both processes require a heavy and strong tank. While a 700 bar tank is acceptable for a city bus or a truck, adapting it for use in small vehicles is very difficult because the pressure during refilling would be too great.

The solution? Powerpaste.

A German team of researchers, led by Marcus Vogt, have come up with an interesting "powerpaste", which can store hydrogen energy at atmospheric pressure, ready for release when needed. It is so named because it comes in tubes and looks like toothpaste（牙膏）, not in its traditional form of gas.

The main ingredient（原料）of the paste is magnesium hydride, a substance that reacts with water to form hydrogen. The escaped hydrogen can then be directed into a fuel cell, where it reacts with oxygen from the air to produce electric power.

Refueling is very simple, as instead of going to a filling station, drivers and riders can simply replace an empty tube with a new one and refill the water tank.

Given that powerpaste only begins to break down at temperatures of around 250℃ it remains safe even when a vehicle stands in the baking sun for hours.

However, we will have to be patient. Just because researchers have succeeded in developing a new fueling way does not mean that we can expect to see such vehicles on the road anytime soon. It will indeed be several years before this concept is turned into reality.

1. As a fuel, what is the advantage of hydrogen over oil?

A．Refilling empty tanks will be more convenient.

B．It is less likely to worsen global warming

C．More energy can be packed in the same space.

D．It will produce pure water for people to drink.

2. What is Paragraph 2 mainly about?

A．The practical difficulties to use hydrogen as fuel in small vehicles.

B．The detailed processes of adapting a strong tank in small vehicles.

C．The differences in fueling between large vehicles and small ones.

D．The tricks of building strong tanks in small vehicles.

3. The author mentions the refueling process to show that powerpaste is______________.

A．inexpensive

B．powerful

C．convenient

D．environment-friendly

4. Why does the author call on the readers to be patient?

A．Powerpaste-driven vehicles sometimes move very slowly on the road.

B．Practical use of powerpaste-driven vehicles will not come very soon.

C．Powerpaste-driven vehicles can only work after being in the sun for hours

D．It will be years before the researchers work out the concept of powerpaste.

4 . By the year 2050, a fifth of the world’s cities will experience unprecedented climate conditions and environments that currently don’t exist in any major cities, according to new research. A team of scientists at the Crowther Lab in Switzerland produced the report, which described the climate for 520 major cities 30 years in the future.

The results showed that 77 percent of the world’s cities will experience a surprising change in climate conditions by 2050, and 22 percent of the 520 cities will see conditions that are not currently experienced by any existing major cities.

In China in 2050, the climate of Xi’an, in Shanxi province, will be similar to that of current day Maseru, the capital city of Lesotho in southern Africa, with the maximum temperature of the warmest month likely to increase by 4.59℃. Chongqing in southwest China will resemble the climate of Swaziland capital Mbabane, as the warmest temperature is predicted to rise by 5.1℃.

Scientists predict summers in Europe will get warmer by an average of 3.5℃ and European winters will see temperature rises of 4.7℃. London’s climate will be more similar lo Barcelona, and Madrid’s to Marrakech.

The Crowther Lab hopes the analysis will motivate decision-makers to take necessary steps to prevent or address some of the climate effects due to the threat of climate change. The report also found that cities in tropical regions will experience smaller changes in average temperature but will be controlled by shifts in rainfall regimes. This may lead to a noticeable increase in unexpected events, and severe droughts.

“Across all scientific fields, the greatest challenge in climate science is no longer the precise measurement of climate change impacts, but inspiring people to picture is actual effects in order to motivate action,” said Tom Crowther, senior scientist und founder of the Crowther Lab.

1. According to the research, among the 520 cities by 2050, about ________ cities will experience the climate conditions that no major cities currently have experienced.

A．400

B．114

C．260

D．104

2. How did the scientists prove their result?

A．By listing figures.	B．By making comparisons.
C．By doing experiments.	D．By explaining theory.

3. What is the Crowther Lab intended for?

A．To compare the climate change of the major cities of the world.

B．To inspire people to picture its actual effects in order to motivate action.

C．To inspire decision-makers to take necessary steps to prevent some climate effects.

D．To show most word’s cities will experience a striking change in climate conditions.

4. What is the best title of the passage?

A．World Temperature	B．Current Climate Change
C．Big Titles in the World	D．Future Climate Change in Most Big Cities

5 . 阅读下面短文，在空白处填入1个恰当的单词或括号内单词的正确形式。

The 2020 Nobel Prize in Chemistry     1    (award)to Emmanuelle Charpentier and Jennifer A. Doudna recently. The two female scientists won the prize     2     the development of a method of genome (基因组) editing.

Gene editing has a wide     3    (apply) across the world. It can     4     (direct) change the DNA of a lifeform and has the potential of leading to     5    (benefit) results.

One of the most convenient methods of gene editing is called CRISPR/Cas9,     6     was discovered by the two Nobel winners. The method enables scientists to cut a sequence of DNA into two pieces,     7    (allow) nature to “repair” it. During the repair process, errors will be introduced to create a different sequence of DNA, thus resulting in an     8    (edit) gene.

In simple words, CRISPR/Cas9 is the “scissors” of genes. The greatness of CRISPR/Cas9 lies in extreme accuracy. It also enables humans to breed (孕有) more plant varieties and develop better treatment of cancer.

In the future, the discovery     9    (expect) to have a revolutionary impact on the life science and make the dream of curing some diseases come true.

There will be no traditional Nobel Awarding Ceremony in Stockholm this year due to the COVID-19,     10     an online version will be held instead.

6 . Directions: Read the following passage. Summarize the main idea and the main point( s) of the passage in no more than 60 words. Use your own words as far as possible.

It's undeniable: Being among the first to try out a new piece of technology is cool. There's the excitement of doing what has never been done before-the feeling that you're living in the future. And when you're the sole member of your social circle with the latest hot gadget, people stare in fascination. They ask you questions. They see you as the holder of powerful, secret knowledge-for a little while, until the next big thing comes along. People tend to underestimate the costs of this temporary coolness, which they pay in more ways than one. Don't fall into the early adopter trap. Don't join the first wave of consumers who invest in the latest media-hyped hardware; instead, wait and see.

To put it frankly, early adoption is a bad investment. First, the earliest versions of devices are not only expensive, they are also the most expensive that those devices will ever be. Companies are presumably attempting to recover the cost of production as fast as they can, and they know that there are serious tech-lovers who will pay a great deal to be first. Once the revenues from early adopters' purchases are safely in their hands, they can cut the price and shift to the next marketing phase: selling the product to everyone else. This is why the cost of the original iPhone dropped about U. S. $200 only eight months after its release. Plus, electronics hardly ever become more expensive because intense competition in the industry puts downward pressure on prices over time. Prices of gadgets will fall shortly after release, and they will likely keep falling. Many new TV models drop significantly in price as little as ten days after hitting the market. Further, electronics rapidly depreciate because they become obsolete (废弃的)so quickly. This means that early adopters pay the maximum price for an item that does not hold onto its value. The resale price of a cell phone or laptop can drop by fifty percent within just a few months.

Speaking of becoming obsolete, those who are first to leap into a new technology risk (三野志) wasting money and time on something that will never catch on. Another good reason to resist the early-adoption temptation is that the first version of a product typically has defects that cost a lot in time and frustration. Such problems are so common with new technology that early adopters are basically unpaid beta testers and troubleshooters. Unless this sounds to you like a fun way to spend your time, don't be among the first users. If you wait to learn what the problems are with a new electronic gadget, you can look forward to a smoother experience—or choose a less troublesome product.

___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

7 . Smart cities are coming. And you can be sure that hackers (黑客) won’t be very far behind. We’ve already gotten a glimpse of that future, as cities across the globe start to use technology to connect their services and people in ways that were science film just a few years ago. They are using sensors to collect data — such as traffic, garbage collecting, and road conditions —and then using that data to deliver services to more people and more efficiently.

But this rush to become a smart city has a major weakness: The more connected a city is, the easier it is to cyber-attacks. Hackers have, in recent years, effectively held cities hostage through ransom ware (赎金器), sometimes damaging critical systems for months at a time. The damage can cost millions to repair, as Baltimore and Atlanta have discovered.

And this is just the beginning. As cities add connectivity to their streetlights, power grids, dams, transit lines and other services, they are adding more targets that are possible to be hacked. What’s more, as additional information on people is collected, officials worry the result —lots of data could attract nation-states or terrorists who could use the data to launch physical and cyber war.

What cyber security lesson can’t be taught in this hack? For example: Don’t open email attachments from unfamiliar sources; don’t click on unrecognized links; don’t leave sensitive information visible on the walls or surfaces of your office.

But let’s just stick to the most important lesson: The information you share on social media can be used to profile and target you, whether that’s by engineering click bait (点击诱饵) aimed at your particular interests, guessing your password based on your birthday or figuring out your schedule and travels so that an intruder can access your home or office.

Wednesday, September 18, 2019 THE WALL STREET JOURNAL.

1. What did people use to think of smart cities?

A．It was the product of science.	B．It was sure to be popular.
C．It existed in imagination.	D．It improved people’s life.

2. What does the author intend to do in Paragraph 3?

A．Introduce the harm of hackers.

B．Show the danger of a smart city.

C．Add some background information.

D．Summarize the previous paragraphs.

3. What is officials’ attitude to big data?

A．It is convenient to provide service.

B．It is certain to bring about progress.

C．There are actually potential dangers.

D．There’s competition in high technology.

4. What does the underlined word "profile" in Para.5 mean?

A．Describe.

B．Protect.

C．Impress.

D．Fund.

8 . What if the Moon had never existed? For starters we know that the geophysical and climatological history of the Earth would have been different. Although there is still large uncertainty about how the Moon was formed, the most currently favored theory describes a disastrous collision between the Earth and another planetary object.

That event forever changed many aspects of the Earth's evolution. For example, with a relatively large natural satellite putting gravitational tidal forces (潮汐力) on it, the Earth's spin behavior has been quite different than it would have been otherwise. Day length has increased more rapidly than without a moon. And the natural changes in the direction of the Earth's spin axis (轴)-its poles-have been less than they would have been otherwise. A shorter day length and axial variations like these would have changed the Earth's climate history, and almost certainly have changed the way any life evolved.

But if a species like us had still appeared, its landscape for space exploration would also have been completely different. Without a large natural satellite, a mere quarter of a million miles away, there would have been no "easy" trip to make to another world. If there had been a first human mission to another world, it would likely have been to Mars. But this would surely have called for far more extensive designing of spacecraft and life-support systems for deep space. Perhaps instead the initial focus would have been entirely on Earth-orbiting equipment for people and robotic missions to other worlds. Or, maybe the attraction of the seemingly near impossible would still have encouraged these humans from an alternate reality to take the great leap to Mars as their first step outwards.

It is of course, impossible to know exactly what our world would really be like without the Moon-both physically, and in terms of human exploration. But one thing does seem clear: we probably take our natural satellite's existence far too much for granted. Not every inhabited planet in the universe will have its own ready-made gateway to the universe.

1. Why does the author use the question at the very beginning?

A．To introduce the widely accepted theory.	B．To mention the destructive collision.
C．To prove a wrong assumption.	D．To attract readers' interest.

2. What does the author intend to do in Paragraph 2?

A．Compare day lengths in different climates.

B．Introduce the evolution of life on the Earth.

C．Explain why the Earth's spin behavior remains.

D．Show how the Moon greatly influences the Earth.

3. What does the underlined word "this" in Paragraph 3 refer to?

A．The Earth's evolution.	B．The mission to Mars.
C．The trip to the Moon.	D．Earth-orbiting equipment.

4. What's the author's purpose in writing the text?

A．To call on people to study the Earth.

B．To stress the significance of the Moon.

C．To speak highly of human exploration.

D．To prove assumptions about moonless Earth.

9 . In the future, when robots can be used both in homes and in other areas, they could improve the living standards of people.     1     When robots can complete such jobs, people can spend more time with their family and friends.

Experts believe robots can be used on certain jobs to avoid accidents caused by careless behavior of some people. When robots are used on such work, it does not risk any human life due to accidents at the workplace. Human resources can be efficiently used by performing tasks which demand human skills like critical thinking and problem solving.     2    

While some people talk about how robots can be useful to humans, others voice their concerns. When robots become cheaper to produce, employers may prefer to use more robots than humans. As the technology constantly improves the abilities of robots, it could weaken the value of humans.     3     Some may even develop the habit of using robots on tasks that they can easily do. This could create a lazy society.

    4     Without them, the nation’s health care system will break down. There will simply be too many elderly people to care for as the nation faces a decreasing birth rate, an aging population, and the loosening of family ties.     5     Above all, Japan needs its dreams of robots in the home to come true because its immigration policy is anti-immigration.

A．Robots have been widely used in Japan.

B．Many people may rely on robots heavily.

C．They can free people from such tasks as cooking.

D．Most people believe robots have changed their life.

E．Japan sees it as a must to build robots to take care of the elderly.

F．Robots can be also used on low-end jobs like moving heavy things.

G．However, many elderly people would prefer human helpers to robots.

10 . Cloud computing will be in use by about 80 percent of about 600 companies. The trend suggests that data management and storage are moving to cloud computing sellers on a large scale.

Touting(兜售)cloud computing as a way to get rid of the costs of buying and maintain in on-site information-technology equipment, sellers offer it in the form of Software AsA. Service(SAAS), a delivery model in which software applications are delivered to customers over a web-based network. SAAS can serve the needs of entire companies through huge, web-based platforms. As cloud computing rapidly bccomes the delivery channel for software developers of all shapes and sizes to get their products to market, offering applications in a cloud is now the rule not the exception. A. relatively small number of sellers are able to offer SAAS to big companies that want company-wide cloud computing, and only the sellers need apply. Although market-share data are hard to come by, the list of company’s large enough to offer cloud-computing on this scale is short: Microsoft, Amazon, Google, Salesforce, Rackspace and not many others.

The concentration of data and virtual (虚拟)computing in the hands of relatively few sellers raises an important risk for their customers if the Internet-based systems of any one seller are hacked, the result could be security problems across entire industries in which their customers do

Can this small group of cloud-computing sellers effectively respond to the needs of their customers to quickly fix such a problem and, most importantly, cut off the damage to these companies' own customers? Don't think such things can't happen. If hackers can penetrate the Department of Defense, the risk that they will penetrate Microsoft or google cannot be ruled out Compromise of just one of these sellers---even one with a modest market share---possibly could shut down, at least temporarily, a sizable part of the U. S. economy.

1. What can cloud computing do？

A．Reduce the cost of computers.

B．Provide software service.

C．Market various products.

D．Help companies design websites.

2. What do we know about cloud computing？

A．It works under SAAS.

B．It covers a large part of market-share.

C．Most companies can provide it.

D．Most sellers apply for it.

3. Why is the Department of Defense mentioned in the last paragraph？

A．To warn people of the hackers' power.

B．To show relationship between it and microsoft.

C．To give an example of the country's loss.

D．To present the real picture of the U.S.economy.

4. What might be the best title for the text？

A．The Unthinkable risks of the cloud.

B．Cloud Computing and Smart Sellers.

C．SAAS and changing Companies.

D．The Cloud Computing Age.