2 . 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.

3 . Swimming in an ocean of stars

Ladies and Gentlemen,

It’s my great honor to receive the Clarke Award for Imagination in Service to Society. Thank you.

I started writing sci-fi because I looked for a way to escape the dull life, and to reach out, with imagination, to the mysterious time and space that I could never truly reach. But then I realized that the world around me became more and more like science fiction, and this process is speeding up. Future is like pouring rain. It reaches us even before we have time to open the umbrella. Meanwhile, when sci-fi becomes reality, it loses all its magic, and that frustrates me. Sci-fi will soon become part of our lives. The only thing I can do, is to push my imagination further to even more distant time and space to hunt for the mysteries of sci-fi. As a sci-fi author, I think my job is to write things down before they get really boring.

This being said, the world is moving in the direction opposite to Clarke’s predictions. In 2001, A Space Odyssey, in the year of 2001, which has already passed, human beings have built magnificent cities in space, and established permanent colonies on the moon, and huge nuclear-powered spacecraft have sailed to Saturn. However, today, in 2018, the walk on the moon has become a distant memory. And the furthest reach of our manned space flights is just as long as the two-hour mileage of a high-speed train passing through my city.

As a sci-fi writer, I have been striving to continue Arthur Clarke’s imagination. I believe that the boundless space is still the best direction and destination for human imagination. I have always written about the magnitude and mysteries of the universe, interstellar expeditions, and the lives and civilizations happening in distant worlds. This remains today, although this may seem childish or even outdated. It says on Arthur Clarke’s epitaph,“He never grew up, but he never stopped growing.”

Many people misunderstand sci-fi as trying to predict the future, but this is not true. It just makes a list of possibilities of what may happen in the future, like displaying a pile of cobblestones for people to see and play with. Science fiction can never tell which scenario of the future will actually become the real future. This is not its job. It’s also beyond its capabilities. But one thing is certain: in the long run, for all these countless possible futures, any future without space travel is gloomy, no matter how prosperous our own planet becomes.

Sci-fi was writing about the age of digital information and it eventually became true. I now look forward to the time when space travel finally becomes the ordinary. By then, Mars and the asteroid belts will be boring places and countless people are building a home over there. Jupiter and its many satellites will be tourist attractions. The only obstacle preventing people from going there for good, will be the crazy price.

But even at that time, the universe is still unimaginably big that even our wildest imagination fails to catch its edge. And even the closest star remains out of reach. The vast ocean of stars can always carry our infinite imagination.

Thank you all.

1. What does the writer mean by the underlined sentence in the second paragraph?

A．Science technology has been developing fast before we realize it.

B．What happened in our life was mysterious and beyond our imagination.

C．We had a good outlook for the future and were desperate to realize our dream.

D．We managed to escape from the boring life and looked forward to the prosperous future.

2. What can we learn from the third paragraph?

A．What Clarke foresaw is childish and out of date, going against scientific theories.

B．It is feasible for human beings to fulfill challenging space missions that Clarke forecast.

C．Human beings have deserted imaging and exploring the attractive and boundless space.

D．Clarke’s predictions haven’t happened in real life and the reality won’t change very soon.

3. According to the passage, which of the following statements is true?

A．What is written in science fiction can never become a reality.

B．The writer considers it his duty to create sci-fi with author Clarke.

C．Science fiction provides readers with possibilities that future will bring about.

D．High price will likely stop humans from dreaming of living on other planets.

4. What’s the writer’s attitude towards sci-fi creation?

A．Curious	B．Passionate
C．Concerned	D．Suspicious

4 . Directions: after reading the passage below, fill in blanks to make the passage coherent and grammatically correct. For the blanks with a given word, fill in each blank with the proper form of the given word; For the other blanks, use one word that best fits each blank.

Could we have zero deaths on our roads?

Cars that can think for themselves have clear advantages     1     flesh-and-blood drivers. They don’t get drunk or drowsy, daydream or get distracted by mobile phones.

Human error causes over 90 percent of these collisions. Driverless cars, which     2     sense other vehicles on the road as well as obstacles and lane markings(车道标记), are already proving much safer than human-driven cars. In trials of Google’s autonomous Prius fleet in Silicon Valley in California, the only accidents     3    (cause) by human error. How are innovations like these designed? And how safe is it    4     (put) your life in the hands of an autonomous vehicle that makes all your decisions for you?

Driverless cars use a mix of GPS, cameras, complex scanners and sensors to detect vehicles, traffic signals, curbs, pedestrians and    5     obstacles. “A central computer system analyzes the data to control acceleration, steering and braking,” says Olivier Sappin, VP of Transportation & Mobility at Dassault Systèmes—the software company whose 3D EXPERIENCE platform and industry solutions are used by motor manufacturers to design, produce and maintain driverless cars. The software can simulate different eventualities(可能发生的事情) to ensure safety on the road—and the results can be incorporated （被包含）into the design and production process.

As well as     6    (detect) their surroundings using ultra-sophisticated mapping systems, future cars will be able to communicate with each other,     7    (allow) as many cars as possible to fit on the roads.    8     (connect) vehicles will feature safety warnings that alert drivers of potentially dangerous conditions—impending(迫在眉睫的) collisions, icy roads and dangerous curves.

Experts say it’s not the technology holding us back, but legal and practical issues such as who is responsible in the case of an accident, urban planning and the security of car computer systems.     9     these details are worked out, and motor manufacturers have used sophisticated software tools to eliminate all potential problems, it won’t be long     10    we’re all a lot safer on the roads.

5 . Many people have long   dreamed of being able to fly around as simply as riding a bicycle.

Yet the safety and strength of a flying bike was always a big problem. Over the past 10 years’ developments in technology have moved the dream of personal flying vehicle closer to reality. Now, two groups of inventors say such vehicles may be available very soon .

Grant Stapleton from Malloy Aeronautics says the Hoverbike, which is able to get in and out of small spaces very quickly, will be a truly personal flying vehicle. " It can be moved across continents very quickly because it can be folded and packed, " he adds.

Mr. Stapleton says safety was the company's main concern when developing the Hoverbike, He says the designers solved the safety issue by using overlapping rotors （折叠旋翼）to power the vehicle. The company is testing both a one-third size model and a full-size prototype （原型)）of the Hoverbike.

Inventors say their Hovebike will most likely be used first by the police and emergency rescue teams.

In New Zealand, the Martin Aircraft Company is also testing a full-size prototype of its personal flying bike, called Jetpack. It can fly for more than 30 minutes, up to 1,000 meters high and reach a speed of 74 kilometers per hour.

Peter Coker is the CEO of Martin Aircraft Company. He said Jetpack " is built around safety from the start ” In his words, reliability is the most important part of it. We have safety built into the actual structure itself very similar to a Formula One racing car."

Jetpack uses a gasoline-powered engine that produces two powerful jet streams. Mr. Coker says it also has a parachute （降落伞）that can be used should there be an emergency.

"It opens at a very low altitude and actually saves both the aircraft and the pilot in an emergency," he adds.

1. Which of the following words can best describe the Hoverbike?

A．Powerful.	B．convenient
C．graceful	D．available.

2. What make（s）flying vehicles seem practical now?

A．Modern technology.	B．New safety rules.
C．Love of cycling.	D．Public concerns.

3. Who are expected to use the Hoverbike first?

A．People who dream of flying.	B．People who really love cycling.
C．people who design the bike.	D．People who serve public purposes.