本场托福考试，ETS很友好地给出了高频综合写作话题：影响动物数量的方法。动植物数量的增减，是综合写作频繁出现的主题，有多道TPO题目都涉及相关考点：TPO10、15、17、18、21、23、42、48等，都和本期考题有相似之处。因此，TPO仍然是考生备战综合写作的重要资料。
Keywords: population, predator, barrier, productive, pollination, mate
可以类比下列这些TPO的综合写作。
TPO15 Reducing Cane Toads in Australia
阅读部分：
总观点：有三种方法可以减少澳洲cane toads的数量：
• 设置物理屏障；
• 组织志愿者抓cane toads；
• 放病毒。
听力反驳：
这三个方法都不好。
• 物理屏障无法阻挡cane toads的卵或是幼蛙顺着河流飘到屏障之外；
• 志愿者可能会误抓当地的frogs；
• 病毒会造成生态紊乱。
TPO21 Genetically Modified Trees
阅读部分：
总观点：大量种植基因修改的树木会带来很多好处
• 基因修改的树木更容易生存。比如说，某种基因修改的papaya tree更容易抵制害虫（pest-resistant）；
• 基因修改的树木能够带来更大的经济效应，因为它们生长的更快，果实更多（greater returns）；
• 基因修改的树木可以预防过度砍伐，因为大量的此类树木可以满足日益增长的木材需求，从而减少濒危树木（endangered native trees）的砍伐。
听力反驳：
总观点：运用基因修改的树木会带来问题和花费（cost）
• 基因修改的树木可以抵制某种疾病，但是并不能保证树木的生存能力更强。因为它们的多样性（diverse）不如自然树木，所以无法应对更多的自然挑战（environmental challenge）或是新型害虫（new pest）；
• 种植基因修改的树木有一些隐藏的花费（hidden cost）。这类树木的种子比非基因修改的树木贵很多。此外，人们每次种植新的树木，都需要从公司购买种子，而不能从已有的基因修改的树木上收集种子；
• 基因修改的树木会对当地的树木造成严重的损害。因为它们的生存能力比自然生长的树木（natural tree）强很多，所以它们会抢走更多的资源，如阳光、土壤、水等。
有一些观点是影响动植物数量类话题中非常常见的：如感染疾病，捕食者/被捕食者，迁徙，资源等等。考生需要掌握以下高频词汇：
² 病毒（virus, bacteria）
² 杀虫剂/有毒物质（pesticides/ toxin）
² 隔离/迁徙/引入（isolate/ migrate/ immigrate）
² 捕食关系（prey, predator, hunting）
² 资源（resources, 如food, nutrient, water, sunlight）
题目解析：
1月31日的独立写作讨论人们购物的动机。虽然是一个与个人生活高度相关的话题，但不少同学反映思路纠结，无从下笔。在练习和考试时，如出现这种情况，建议借助构思法梳理、拓展思路，再比较同意、不同意两方能够想到的分论点，选择好成文的立场展开。本题同意的理由可以写人们需要融入群体、同伴压力、想要展示自己或是商家宣传等；不同意的理由可以写人们沉迷购物另有原因，比如个人需求、兴趣、整体经济状况较好等。
段落安排可以采取两种形式：，一边倒，即所有主体段均支撑自己的主观点；第二，写一个让步转折段，再组织两个正面论述段。
请参考如下范文：
Contemporary society has witnessed an all-encompassing market and unprecedented shopping mania during past decades. In peak seasons such as Black Friday or Christmas, the sales volume in America, both online and offline, can be as stunning as several billion dollars. So, what drives people to be so passionate in purchasing goods? Some argue they have to own certain things or they might be looked down by others. However, I don’t think that’s the main motivator behind astonishing shopping boom today.
Admittedly, few people can completely ignore judgement from their surroundings and do everything according to their own will. Afterall, human beings are social creatures that need to fit in certain groups as well as gaining acceptance. Therefore, it is not surprising to hear that some individuals, mainly the young, purchasing luxuries at the cost of a bad financial balance. Nor do audience feel confused when commercial advertising or fashion bloggers connect so-called must-have goods with the images of successful or attractive figures. However, the worries of being judged by others play a minor role when people make their shopping lists. Instead, some stronger influencers should be noticed.
To begin with, in most cases, the prerequisite for purchasing is that people really need certain goods. Otherwise, they may not even bother to learn about those products. In other words, no matter what judgement one may receive, there is a tiny chance that they will buy things that are useless to them. For instance, many articles articulate how to tell people’s social class or background according to their accessories such as watches or jewelries. However, a researcher who works in a pharmaceutical firm might have little interest in them because he needs to wear uniform or even special garments in his workplace. If he has to take off his watch in this worktime, why bother buying an expensive Longines with diamonds inlaid?
Another strong stimulus of shopping is the affection buyers cast on the goods they pick. Expensive belongings do elicit admiration from others. However, the happiness generated from what customers truly enjoy can always outcompete vanity. For instance, my friend Vivi is a huge Disney fan. Some of her friends frequently urge her to buy a Chanel purse or LV handbag because “every girl needs some luxuries”. However, she keeps choosing products from Disneyland, even though she can afford expensive bags. She said:” Whenever I feel exhausted or dismayed, Donald Duck or Dumbo on my bag can easily remind me of the happiness I fell in Disneyland. Then, I can cheer up and continue working with a lighted heart.”
It is true that others’ judgment sometimes plays a role in one’s purchasing. Nevertheless, I think one’s own demand and feelings are the main reasons why people are obsessed in buying things.
（新航道武汉学校 北美考试院 托福写作组 崔国花）
