TPO54

Directions: You have 20 minutes to plan and write your response. Your response will be judged on the basis of the quality of your writing and on how well your response presents the points in the lecture and their relationship to the reading passage. Typically, an effective response will be 150 to 225 words.

Reading Part

The Salton Sea in California is actually a salty inland lake. The level of salt in the lake's water --- what scientists call its salinity --- has been increasing steadily for years by rainfall or rivers. If the trend continues, the lake's water will soon become so salty that the lake will be unable to support fish and bird populations. The lake would then become essentially a dead zone. Fortunately, there are several ways to reverse the trend that is threatening the lake's health.

One option is direct removal of salt from the lake's water in special desalination facilities. Water from the lake would be pumped into the facilities and heated. This would cause the water to evaporate into steam, while salt and other materials dissolved in the water would be left behind. The steam would then be cooled down and returned to the lake as salt-free water. Gradually, the high salt levels would be reduced and the lake's overall health would be restored.

Another possible solution is to dilute the salt level in the lake with water from the ocean. Since water in the Pacific Ocean is 20 percent less salty than the water in the lake, bringing ocean water into the lake would decrease the lake's salinity. The ocean water could be delivered through pipelines or canels.

Yet another solution would be to control the lake's salinity by constructing walls to divide the lake into several sections. In the smaller sections, salinity would be allowed to increase. However, in the main and largerst section, salinity would be reduced and controlled by, among other things, directing all the freshwater from small rivers in the area to flow into that main section of the lake.

Listening Part

Directions: Now listen to a part of a lecture on the topic you just read about.

It would be great if we could stop the lake salt level from increasing and save its fish and bird populations. But the solutions you read about aren't realistic or practical.

First, sure, taking salt out of lake by desalination would reduce salinity, but it would present serious problems as well. For example, as you've read, water pumped into desalination facilities evaporated and leaves behind solid materials that would dissolve in the water. Well, the solid materials that desalination facilities leave behind would pose a health risk. The materials will be mostly salt, but they would also include other types of chemicals. Some of the chemicals would be toxic, like selenum. If the wind spread selenium and other chemicals into the air and people breathe them in, that would be very dangerous to people's health.

Second, the idea of bringing ocean water into the lake, again, this would be reduce salinity. But as you've read, it would require constructing pipelines or canals. The problem is that the local government may not have enough resources to pay for such major constructions. The nearest shoreline of the Pacific Ocean is 100 kilometers away. Pipelines and canals are very expensive to build over such long distances.

As for the third solution, dividing the lake into sections by building a system of walls. Well, that's unlikely to work for very long. That's because the Salton Seas is located in a region that experiences frequent and sometimes intense geological activity, like earthquakes. That activity would almost certainly destory the walss separating the different sections. So while this solution might work for a short while, the walls would likely collapse the first time there is a major earthquake. And water from the special sections with high salinity would mix back in with the low-salinity from the main section.

Question

Summarize the points made in the lecture, being sure to explain how they respond to the specific concerns presented in the reading passage.

Model Essay

The Salton Sea in California is facing a problem that the salinity has been increasing for the rapid evaporation rate. The reading passage has given three solutions while the listening part reveals the leak of them one by one.

The first option is to remove the salt directly from the lake's water by a special desalination facility. However, the professor argues that this method is very likely to cause health problems. As the water in the desalination facilities evaporates, solid materials would be left behind, which contain toxic chemicals, such as seleniums. Then, seperating would allow these chemicals to be spread by wind, which may pose a threat to people's health.

The second solution is bringing ocean water to the lake to dilute the salt level. The professor finds faults with this method by saying that this solution would be quite unrealistic in consideration that the government may not have enough money to build any pipelines or canals. Moreover, the nearest shoreline is 100 kilemeters away, so the constrcution may cost a lot of money.

The last way is to divide the lake into several sections by building walls. The salinity in smaller sections would increase while in largest sections, by directing fresh water from small rivers, the salinity would be controlled. However, the professor refutes that this measure is just provisional, since the Salton Seas is located in place where the geological activities are frequent and intense. Water from the smaller sections may mix back in the main section so this solution will also fail very soon.

258 words

范文分析

这个范文和我自己写的格式还是有一些区别的，可能是我拿低分的原因。

首先是总起的一段，写的比较清晰简单，这样应该能显得文章思路清晰。

然后接下来三个分段，他的写法是用the first option, the second solution, the last way这样来说，而不是我一直使用的First, the author contends that..., Second, the writer suggests that... Third, 然后词穷了，而且我这种写法在字数上比较冗余，缺少对文章意思的凝练。范文中承接下文的那句话“The reading passage has given three solutions while ...”可以和下文的option, solution和way对上，这种方式让读者读起来更加清晰。

进一步分析二三四段落中每段的结构，可以发现他是有着重点的，并没有把阅读材料的内容全部涉及，二三段只有第一句是在讲阅读材料中的内容，第二句立马就However要讲听力材料了，除了第四段他阅读材料说的多了几句，但还是保持了听力材料占多数比例。

转折句和我的写法大差不差，但是他有用一个形容词来凝练一整个反驳段的思路，unrealistic和provisional都是听力材料中没有出现的，是作者直接概括出来的，这说明要积累一些带有反驳意味的词汇。

背景音推荐(《16bits的感动》，就是女主有点吵)：

https://www.yhdmz.org/vp/23323-3-0.html