填空题

Air Pollution
1 In 2002, the Earth Summit was held in Johannesburg in South Afric

• a. One of the main themes of the summit was "sustainable development", or the question how we can continue developing the world without damaging the environment.
  2 In Johannesburg, experts from all over the world spoke about different topics and discussed new ways to solve old problems. Most of the speakers talked about the "big three", the three biggest killers in the world-contaminated drinking water, poor sanitation and air pollution. According to the World Health Organization, the big three cause more than seven million deaths every year. That is 15% of all the deaths in the world. 20% of the people on earth do not have access to clean drinking water. Air pollution alone causes almost three million deaths. Most of these deaths happen in rural areas, where people burn wood and coal to cook food and stay warm. Air pollution is especially a big problem in very large cities, especially in developing countries.
  3 Air pollution can spread from city to city. It even spreads from one country to another. Some northern European countries have had "black snow" from pollutants that have traveled through the air from other countries and have fallen with the snow. So air pollution is really a global problem.
  4 Air pollution can kill babies, older people, and those who have diseases with their breath. As found in cities, air pollution increases the risks of certain lung diseases.
  5 Air pollution can cause both airplane and car accidents because it cuts down visibility. There are other possible health dangers from air pollution that we don’t know much about. For example, scientists are trying to find out whether chemicals that reach us from the air may cause changes in our cells. These changes might cause babies to be born with serious birth defects. Scientists are trying to learn how all the many chemicals we are apt to take into our bodies work. That is another reason why it is so important to begin to control pollution now instead of waiting until we learn all the answers.
  6 Air pollution costs us a lot of money. It corrodes our buildings. It damages from crops and forests. It has a destructive effect on our works of art. The cost of all this damage to our government is great. It would be much more worthwhile, both for us and for the government, to spend our tax dollars on air pollution control.A. Cost moneyB. The big three killersC. We should spend money to control itD. The effect of air pollution to peopleE. Air pollution is a global problemF. The effect of air pollution to works

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