题目内容：

HYDROGEN­POWERED cars have had a rough ride. Back in 2003, they were sold as “one of the most encouraging, innovative technologies of our times” by US president at the time George W. Bush. Then the Tesla revolution came along and they were left in the dust by their battery­driven electric rivals.

Now, there are signs of a comeback. A recent survey of more than 900 global automotive executives by consulting firm KPMG found that 52 percent rated hydrogen(氢) fuel cell vehicles as a leading industry trend. Japan has announced plans to put 40,000 hydrogen vehicles on the road in the next five years, and South Korea 16,000. Germany wants to have 400 refueling stations for hydrogen vehicles by 2025 and California has already opened 35.

This renewed push has its doubts. Tesla chief Elon Musk, for example, has dismissed hydrogen cars as being “extremely silly”. But Joan Ogden at the University of California, Davis, sees a future in which hydrogen and electric vehicles play complementary(互补的) roles. “There are arguments for having both,” she says.

Like electric cars, hydrogen vehicles produce zero pollutants, so they don't damage our health or the climate. The main difference is that hydrogen cars use a fuel cell instead of a battery to power an electric motor. Hydrogen is stored in a tank and fed into the fuel cell, where its chemical energy is changed into electrical energy.

Hydrogen cars are finally becoming commercially practical because fuel cells have become smaller and lighter, says Matthew Macleod at Toyota, which began selling the Mirai, one of the first mass­market hydrogen cars, in 2014 for $60,000.

We are also figuring out better ways to transport and store hydrogen, says Michael Dolan at Australia's national science organization, the CSIRO. Last month, his team showed that hydrogen gas can be changed into liquid ammonia(氨) for transportation, then changed back. Liquid ammonia takes up less space and is less flammable than hydrogen gas, making it easier to ship to refueling stations.

The ability to rapidly refuel is one of the main advantages hydrogen vehicles have, says Macleod. Filling up a hydrogen car takes about the same time as filling a petrol one, rather than the hours it typically takes to recharge an electric car's battery. You can also go further on a full tank of hydrogen—about 500 kilometers, compared with 300 kilometers for a standard fully charged battery.

But although hydrogen reacts cleanly—the only thing coming out is water—hydrogen vehicles are more energy­consuming than electric ones if you take fuel production and transport into consideration, says Jake Whitehead at the University of Queensland, Australia.

At the moment, most hydrogen is from natural gas—a fossil fuel. “Green” hydrogen can be made by splitting water using solar or wind power, but this involves multiple steps, each using energy along the way. In contrast, a single energy step is required to directly recharge a car battery at home.

1.What can we infer from the first three paragraphs？

A. Gorge W. Bush once drove a hydrogen car on a bumpy road.

B. Joan Ogden thinks hydrogen and electric cars can exist and improve together.

C. Japan will have more hydrogen cars than electric cars on the road in the next 5 years.

D. Tesla made a contribution to the popularity of hydrogen cars.

2.The underlined word “flammable” in the 6th paragraph may mean that something is    .

A. heavy to carry    B. fragrant to smell    C. easy to burn    D. bitter to taste

3.What can we know about the differences between hydrogen and electric cars？

A. Comparatively, for hydrogen cars, fuel production and transportation is cheaper.

B. On a fully charged battery, electric cars can cover a longer distance.

C. It takes far more time to refuel hydrogen cars than to recharge a battery.

D. Hydrogen cars use a fuel cell rather than a battery to provide power.

4.What's the author's attitude towards hydrogen­powered cars？

A. Opposed.    B. Approved.    C. Skeptical.    D. Objective.