本文来自雅思作文网liuxue86.com《2005年2月份雅思考试总结(下)》。 FOR （涉及经济、健康、环保、文化等原则）
1. 经济原则：Genetically modified (GM) food is a key area of agricultural biotechnology. Supporters of GM food believe the technology could offer cheaper, safer and more nutritious food.
2. 健康原则：Genetically modified food activists promise gene technology will supply plentiful amounts of food to starvation stricken areas in the Third World.
3. 健康原则：Genetically modified crops (transgenic crops) are best known for their abilities to resist pests (weeds, insects, and diseases) or for produce containing high nutrient levels.
4. 经济和健康原则：Transgenic crops may provide increased profits to the farmer while providing cheaper and more nutritious food.
5. 环保原则：Genetic engineering also has helped make crops available that could not otherwise tolerate adverse environmental conditions (drought, cold, high salt levels in the soils, etc.).
6. 经济、环保和健康原则Such crops are capable of resisting pests, generating higher yields, and producing food with high nutrient content. They are considered an effective means of dealing with pest problems while reducing production costs.
7. 经济原则：A possible benefit of transgenic crops or animals is that they can be bred for desirable traits very precisely and much faster than when traditional methods are used.
8. 健康原则：Certain transgenic crops (e.g., "golden rice" capable of synthesizing the precursor of Vitamin A) are capable of produci...