2010.2.21托福机经写作部分 Independent ： Should all school teachers be required to attend courses every 5 years to update their knowledge? Integrate: Iron fertilization Reading: 1, not efficient, in experiment, only few carbon dioxide could be absorbed. 2, produce toxic chemical materials which will harm the local fish industry. Human beings will be harmed also if they eat those toxic fishes. 3, cause bad impact to ocean biology system. damage ocean's bio-system balance. Lecture: 1, experiment is too short, only for 1 month. Actually, the 2nd and third month, absorption of carbon dioxide will gradually increase. most of CO2 are consumed in the last month which can not be observed in the short experiment. 2, only limited area will generate these toxic materials. stop to use this method in those area then. 3, global warming's risk is greater than regional ocean's bio-system risk. So should concern more about global warming, ignore ocean's biology system damage. 第一段的关键词的确是ineffective，说相关实验也少。而在听力里面反驳的时候说的是那个phytoplankton我记得貌似是个什么浮游植物，这个东西can live 2到3个月。而大多数实验只观察了一个月，所以老师认为如果多观察，等到一个月后就会很明显的效果了。 第二个关键词就是说toxin这个问题。阅读说害鱼还会hurt吃鱼的人（原文hurt）。而听力说的是你只要不fertilize with iron就OK了，至少我听见是这样子的，等你把这些东西种好了不需要了就不要用铁了就没毒了。 第三段是说破坏生态平衡，阅读说的是你不知道你用这个东西会给ocean的生物带来什么，他们会相互影响最后影响整个海洋的生态平衡。而听力说if you don't take this risk就会有great risk，也就是全球变暖气候变化，听力说这个影响更大，而且也会给整个海洋生态系统带来更大的威胁和破坏。 独立写作 Do you agree or disagree with the following statement? All school teachers should be required to take courses every five years to update their knowledge? 以上就是精品学习网为同学们分享的2010.2.21托福机经，更多托福资讯，尽在精品学习网托福频道。如有不完整部分，欢迎同学们致信chenj@51edu.com 补充修正
