A warning system to prevent drivers from falling asleep was introduced at the 2020 China International Fair for Trade in Services,     1     was held from September 4 to 9 in Beijing. The system can judge whether the driver is sleepy by monitoring how long the driver's eyes close. If the driver is tired, the system will sound an alarm until the driver's eyes reopen. In the future, other     2     (danger) driving behaviors, such as not wearing a seat belt and making phone calls while     3     (drive), might also be added into this warning system.

5 . I was desperately nervous about becoming car-free. But eight months ago our car was hit by a passing vehicle and it was destroyed. No problem, I thought: we’ll buy another. But the insurance payout didn’t even begin to cover the costs of buying a new car—I worked out that, with the loan (贷款) we’d need plus petrol, insurance, parking permits and tax, we would make a payment as much as £600 a month.

And that’s when I had my fancy idea. Why not just give up having a car at all？I live in London. We have a railway station behind our house, a tube station 10 minutes’ walk away, and a bus stop at the end of the street. A new car club had just opened in our area, and one of its shiny little red Peugeots was parked nearby. If any family in Britain could live without a car, I reasoned, then surely we were that family.

But my new car-free idea, sadly, wasn’t shared by my family. My teenage daughters were horrified. What would their friends think about our family being “too poor to afford a car”？(I wasn’t that bothered what they thought, and I suggested the girls should take the same approach.)

My friends, too, were astonished at our plan. What would happen if someone got seriously ill overnight and needed to go to hospital？(an ambulance) How would the children get to and from their many events？(buses and trains) People smiled as though this was another of my mad ideas, before saying they were sure I’d soon realize that a car was a necessity.

Eight months on, I wonder whether we’ll ever own a car again. The idea that you “have to” own a car, especially if you live in a city, is all in the mind. I live—and many other citizens do too—in a place that has never been better served by public transport, and yet car ownership has never been higher. We worry about rising car costs, but we’d be better off asking something much more basic: do I really need a car？Certainly the answer is no, and I’m a lot richer because I dared to ask the question.

A warning system to prevent people from falling asleep while driving     1     ( introduce) at the China International Fair for Trade in Services. It can judge whether the driver is sleepy     2     monitoring how long the driver’s eyes close or if his or her head drops.     3     the driver enters a state of tiredness, the system will immediately sound an alarm until the driver’s eyes reopen.

8 . 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.

In 1863, the first underground passenger railway in the world opened in London. It     1    (run) for just under seven kilometers and allowed people     2    (avoid) terrible crowds on the roads above as they travelled to and from work. It     3    (build) using an interesting method. This included digging up the road, laying the track and then building a strong roof over the top. When all those had been done, the road surface was replaced.