Tangshan started to revive itself and get back up on its feet. With strong support from the government and the tireless     1     of the city’s people, a new Tangshan was built upon the earthquake     2     . The new city has become a home to more than seven million people, with great improvements in transportation, industry, and environment. Tangshan city has proved to China and the rest of the world that in times of disaster, people must unify and show the wisdom to     3     and rebuild for a brighter future.

When asked by a TV reporter to talk about air and water quality in his hometown, Qi Mu noted, “The air is great now, and we can take more walks and enjoy being outdoors again.” He felt quite pleased because the villagers were living     1     with nature once more. However, he could not forget about an earlier time when his village had been struggling with a serious air quality problem.

In the 1990s,     2     from a nearby city was usually brought to the village. “How can we make use of this?” the villagers wondered. Soon they found that garbage could be used to feed pigs. “Over the next few years,     3    of pig farms were set up,” Qi recalled. But then nobody in the village wanted to open their windows. “The smell from the garbage and pig waste was making us sick,” Qi said. The numbers of mosquitoes and flies were also horrifying. “Under such circumstances, no single women wanted to marry anyone in our village and move here,” Qi sighed.

The villagers could no longer tolerate the situation. So an    4     was launched and a “clean-up” campaign was added to the government agenda, including     5     large vehicles from passing through the village. Garbage from the city was no longer disposed of in the village, and more trees were planted. “We can all breathe more freely now that the natural beauty of our village has been    6    ,” said Qi.

Driving an electric car     1     to the protection of environment, or so the marketing departments of their makers would have you believe. Yet a report which analyzes car emissions presents a rather different picture. A battery-powered car recharged with     2     generated by coal-fired power stations, it found, is likely to be more harmful. It could cause more than three times as many deaths from pollution as a     3     petrol-driven vehicle.

The study was carried out by the University of Minnesota. The researchers estimated how levels of fine particulate matter (细颗粒物) and ground-level ozone — two important     4     of air pollution — would change when a car is powered by different ways.

It was no surprise that electric cars whose batteries were recharged with power from wind, solar or hydro-electric sources came out to be virtually free from harmful     5    . They were estimated to cause 231 deaths over the course of a year, compared with 878 for petrol cars. Electric cars recharged with power from natural gas-fired stations were also a lot less harmful than petrol-driven ones, with 439 deaths. But if those same electric cars were recharged     6     by coal, they would be responsible for over 3,000 deaths.

Biofuels also caused more health problems than petrol. But diesel, which often     7     concern about pollution, is slightly cleaner than petrol. This is because the study assumes for all cars that emission-control technologies will be more widely used, especially particulate filters which have a remarkable effect on cleaning diesel     8    . Diesel cars are also more     9     of fuel than petrol-driven ones.

Overall, the study shows that electric cars are cleaner than those traditional vehicles only if the power used to charge then is also clean. That is hardly a surprise, but the     10     of the difference is. How green electric cars really are, then, will depend mainly on where they are driven. In France, which obtains more than half of its power from nuclear station, electric cars look like a good bet. In China and some other developing countries, where a large amount of electricity is produced from coal, they may not be so environment- friendly as they are marketed.