4. 自然资源怎样保护?
母题：Fossil fuels, such as coal, oil, natural gas, are used in many countries. But in some countries, the use of alternative sources of energy, including wind and solar power, are encouraged. Is this trend a positive or a negative development? (090530)、
提示：这道题目问的是新能源alternative energy的优缺点。优点：取之不尽用之不竭inexhaustible，更环保environmentally-friendly, 缺点：核能 nuclear power会引发安全事故，水能hydropower会破坏生态环境upset the ecological balance, 太阳能solar power 成本太高，风能wind power会产生次声波污染infrasonic wave.
子题：淡水资源怎样保护?是什么原因导致了石油、森林和淡水资源的紧张，怎样解决?解决环境问题的最佳方法是提高石油的价格吗?(此题已被剑8收录)
5. 交通工具
母题：One long-distance flight consumes fuel which a car uses in several years’ time, but they cause the same amount of pollution. So some people think that we should discourage non-essential flights, such as tourist travel, rather than to limit the use of cars. To what extent do you agree or disagree? (060325, 080405)
提示：这道题目是经典老题，多次在雅思考试中出现。题目中的理由有明显的逻辑漏洞，因为飞机承载的乘客数量和行驶的距离要远大于汽车，因此先驳斥理由，再讲飞机被禁止的后果(旅游业，物流业将会遭到重创)就可以了。
子题：汽车会带来哪些问题?廉价航空是否应当被推广?
6. 食品安全
母题：Some people support the developments in agriculture such as factory farming and creations of new types of fruits and vegetables, while others oppose this view. Discuss both views and give your opinion. (080712)
