双边类大作文，科技类话题
It is known to all that the technological and scientific advances have made greater changes to the range and quality of our food. Some people regard it as an improvement while others believe that the change is harmful. Discuss both views and give your own opinion.
题目来源：2016年6月25日大陆雅思大作文
题目大意：
众所周知，科技进步对我们的食物种类和质量产生许多影响，有些人认为这种改变是一种进步，有些人认为这种改变是有害的，讨论双方并给出你的观点。
思路解析：
这是一道双边类大作文，讨论的是科技对食物的影响。双边讨论类的题目，可以自由讨论双方各自的利弊，你可以同意某一方观点也可以持中立（都同意或都反对）。这道题目不算难，审题时要注意限定范围“the range and quality of food”，科技对食物种类和质量的影响，因此诸如“食物长途运输”的问题不在这道题范围中。观点上我们可以持中立态度，即两边说的都有道理，下面就和大家来看下具体观点~
首先来看好处，主要有两方面。
一是丰富了食物的种类，人们现在可以吃到的食物会比以前丰富许多，比如西瓜在20世纪前因为皮厚肉少籽多等因素并不好吃，但在近百年不断的科学培育下，现在的西瓜皮薄肉多甜度更高甚至有些品种可以做到无籽，因此才变成了现在大众喜欢食用的水果。
二是打破了季节对于食物的限制，以前因为气温、光照等因素决定了食物是否能够正常生长，因此季节因素很大。但是在科技的进步下，通过暖棚、基因改造等手段，以前某些季节才能吃到瓜果蔬菜，现在一年四季都可以吃到。
三是提高了食物的产量，通过杂交等技术，我们在单位面积上能够产出更多的粮食，更多的粮食产量意味着可以养活更多的人口。
然后来看坏处，主要有两方面。
一是产生食品安全问题，在生产过程中违规使用农药、催熟剂等化学用品，会破坏了食物本身的营养甚至使得食物含有有毒物质，这些会对食用者造成危害。
二是诸如转基因食品对于人类本身是否有危害依然没有定论，有的观点认为转基因食品会产生未知的病毒、或是对食用者造成一些未知的危险，在无法确定没有危害的情况下食用转基因食品，对人类来说是一种风险。
提纲：
范文示例：
Scientific advances have an impact on many aspects of our lives, including food. I believe that the increase in food varieties can be beneficial to mankind, although there are some problems.
The development of food technology can be beneficial to the health of many people. This is because they are provided with a wider range of high-quality choices to adopt a balanced diet. For example, some perishables such as fruit and vegetables can be preserved and made available for people in cold climates.Some diet supplements have also been developed to improve the nutrition of our diet and promote our well-being.
On the other hand, some people argue that the application of advanced food technology can pose health risks, although it can give us more options in our diet. Genetic engineering, for instance, modifies the genetic characteristics of natural crops, but the health consequence of eating these crops is yet to be known. In addition, some chemicals have been used to increase the shelf life of some foodstuffs, despite the fact that these chemicals can harm our health.
In my view, the agricultural industry is able to feed a growing population because of technological advances. The main reason for this development is that technology makes a variety of crops resistant to pests and diseases and also enables these crops to grow faster. This can boost food production. These emerging technologies are especially important for developing countries or heavily populated countries, where many people suffer from malnutrition.
相关词汇和语法结构：
Perishable 易腐物品（食物）
diet supplements 饮食补充剂
improve the nutrition of our diet 改善饮食营养
Genetic engineering 基因工程
increase the shelf life 延长保质期
feed a growing population 养活增长的人口
heavily populated countries 人口密集度高的国家
malnutrition 营养不良
