TPO 21
阅读解析与听力预测
总论：
文章说得非常清楚：Planting genetically modified trees…bring…benefits.下文肯定会展开各种benefits。
好处1：
基因改良后，树hardier，更容易成活。列举了一个改良后的papaya抵御某virus的例子。
好处2：
基因改良让农户受益更大，原因是基因改良后的树生长快，产量高，成活率高。
好处3：
基因改良提供充足树木供人类使用，间接保护wild trees。
听力解析
Sure，there are some benefits说明文章一开始竟然是个让步。这并不重要，接下来肯定会反驳。but are these trees as really great as they first sound表明作者要质疑了。可是我们早就知道了，所以这是废话，不需要记录。there are some problems继续是废话。反正听力是要否定这些benefits的。
First，准备考虑hardy的问题。may be resistant to one particular condition，体现了让步。does not…ensure their survival，听力的策略是承认一定程度上的hardy，但不认为hardy可以决定survival。那接下来肯定要说还有什么原因阻碍了survival，这肯定是modify不能解决的。a typical non-modified trees' population is genetically diverse，不确定要说什么，得记下来。for most threatening…there will be at least some…trees…that are resistant，好像是在说非改良的树本来就有resistance。So even if most…are killed，those few resistant trees will survive and ensure the survival of that species，是废话。但还没明白这和modify有什么关系。But…modified trees are genetically much moreuniform，这里肯定是关键了，改良的树不够diverse，那肯定暗示survival rate反而会下降。So if they are exposed to an environmental challenge they haven't been designed for，我们知道接下来肯定要说，这些树要死了。they'll all die，果然如此。So if the climate changes…这里肯定是举例了，是要说这些情况可能会让modifiedtrees死掉。likely to be completely wiped out，这已经是我们知道的了，不需要记录。
♦ 本段逻辑梳理：确实，modification能让树在某些情况下resistant，但并不见得增加survival。因为没modify的树更diverse，面对threats时总会有某些树活下来，保存整个物种。但modify的树更uniform，面对意外的threats时很可能全部死掉。
as to the second point，准备听与农户受益相关的问题。hidden costs associated with growing genetically modified trees，其实听到这儿的时候确定不了是cost，clause还是cause，所以得听下文来确定。company…charge…more，原来是说那些种子公司会向农户收更多钱，那反驳策略基本清楚了，就是指出其实种改良种子反而代价更高。“…as you've grown the tree，you can't just collect the seeds and plant the new trees for free.”种完后长出来的树的种子还是不归农民，没有良心的资本家！这里其实还是在说代价。那肯定暗示，农户每一轮种植都要给钱。“By law，you have to pay the company every time you plant.”这是废话，好替农户心痛。
♦ 本段逻辑梳理：显然，本段的策略是直接否定种改良植物让农民受益更大，理由是代价更高。代价来源于，这些改良的种子本来就更贵；其次，每轮种植，法律规定都需要继续付钱给种子公司。
Finally，提示要讨论最后一点，关于保护wild trees。might actually cause even more damage to…wild trees，要直接否定阅读理由了。“…often grow more aggressively than natural trees… planted among natural trees.As a result…outcompete…for resources…”这些信息已经明确地说明为什么改良植物对当地植物有危害。因为改良植物疯长，会彻底战胜当地植物。nutrients and water这些都只是例子，说明改良植物战胜当地植物体现在哪些维度上。
♦ 本段逻辑梳理：改良植物反而更可能会伤害当地野生植被。因为改良植物长得更快，加之它们通常种植在当地植物中，所以改良植物会吸取更多的各种资源，比如水、养料，于是outcompete当地野生植被。
满分范文
The article claims that planting genetically modified trees offers three advantages，all of which are denied by the lecturer.
To begin with, while the lecturer admits that genetic modification might render a tree species more resistant under certain conditions, she does not believe as the article does that it necessarily offers the trees more survival advantages. Her reason is that, because unmodified trees are naturally diverse, at least some will survive under external threats and guarantee the survival of the entire species. In contrast, since modified trees are genetically more uniform, when unexpected threats occur, the whole species might easily be wiped out.
Second, the lecturer simply does not believe that planting genetically modified trees are financially more profitable for farmers, because the companies selling the seeds tend to charge more for these modified species. Furthermore, she points out that the law requires the farmers to pay the company each time they plant, adding on to their expenses.
Finally, contrary to the article, the lecturer argues that planting genetically modified trees might actually harm local wild trees. She notes that the modified species tend to grow faster, so when planted among native species, they would outcompete local species with regard to resources，like water and nutrients.