【答案解析】{{B}}MODEL ANSWER 1{{/B}} I agree with the idea that increasing the cost of fuel is the best way to solve the world's environmental problems and will outline my reasons in this essay. When we talk of environmental problems, we talk of a wide range of issues including poilution and species extinction. Although other environmental issues are important, I think that the problem of pollution is the greatest, because it is the main cause of global warming, which in turn creates numerous other environmental problems. Pollution also causes health problems for people that are expensive for individuals and governments to deal with. In order to reduce pollution, we can either ban the use of fossil fuels or increase their price. Banning them is not a good idea. In the short-term, it would leave us without energy and this would undoubtedly result in economic chaos. Even in the medium term it would be a serious problem, since it is not currently Possible to completely replace fossil fuels with "green" ones. For example, replacing petrol-driven cars with ones using electricity produced using "green" forms of energy is possible, though it would take years to achieve. However, there is currently no suitable replacement for using oil to power aircraft. By increasing the price of fossil fuels, we can enable change to take place. With the increase in the price of fossil fuels, "green" energy sources will become more attractive financially. We can see this happening at the moment. In recent years, the price of oil has risen, making "green" energy relatively less expensive. This has led many companies—including oil companies—to look more closely at ways of generating 'green' energy and using it, for example, in cars. Therefore, I believe that increasing the cost of fuel is the biggest step we can take towards aiding the environment. 301 words {{B}}MODEL ANSWER 2{{/B}} I disagree with the suggestion that increasing the price of fuel is the best way to solve the world's environmental problems. Although it is not a bad idea, I believe that population control is the best policy. Whilst increasing the price of fuel should reduce the amount we use, and thereby the amount of pollution we cause, I believe that what we humans really need to do is to use less of the world's resources— fossil fuels, forests, fish, etc. Environmental problems are caused because we use too much of everything. Many species are dying out because we use them as food (e.g. certain species offish) or because we encroach on their habitats (e.g. tigers). Low levels of pollution would not cause great problems such as global warming. In my opinion, the best way that we can achieve the aim of solving these problems is by reducing the number of people so that fewer people can live better. One of the main reasons that China introduced a "one-child policy" is that the Chinese government could see that an expanding population would make unrealistic demands on the natural resources of the country. Many people are worried by this suggestion because they fear that there will not be enough people to continue to make economic progress. This fear appears to be unfounded, since Japan, for example, has a falling population, yet continues to make economic progress by investing in technology (e.g. robots) that can take over the work that humans have been doing. Therefore, whilst I believe that we can do many things to solve the world's environmental problems, the most important thing to do is to reduce the world's population through family planning and thereby reduce our demands on the world's resources. 292 words