托福official54听力conversation1 原文解析+翻译音频

    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 selenium. Then, separating 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 kilometers away, so the construction 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.
 

According to the reading passage, the Salton Sea in California is facing an issue that the salinity has been increasing at a rapid rate, and it has proposed three effective methods. Nevertheless, the lecture argues that the solutions mentioned in the reading are not practical.

Firstly, one of the most direct solutions is to remove the salt from the lake water by using special desalination facilities. Therefore, the salt will be left and the steam will return to the lake as salt-free water, which minimizes the salt levels. By contrast, the lecture retorts that this will lead to serious problems. The solid materials, left behind in the process of evaporation, contain many toxic chemicals, such as selenium. Without any doubt, the wind is likely to spread those poisonous chemicals into the air and people will breathe them in, which poses a threat to their health.

Secondly, the reading asserts that using ocean water to decrease the salt level is also a viable plan, as water in the Pacific Ocean is less salty. On the contrary, the lecture contends that the construction of pipelines will be a major challenge, because the government may not have adequate budgets for these pipelines or canals. Furthermore, the nearest shoreline is 100 kilometers away from the Pacific Ocean, which means that the construction project may be quite expensive.

Thirdly, the reading alleges that it is effective to divide the lake into different sections by building walls. The main reason is that, in the largest sections, the salinity will be controlled by directing fresh water from small rivers. Nonetheless, the lecture points out that this measure is not sustainable. The Salton Seas is located in a place where geological activities like earthquakes are frequent and intense, which will certainly destroy the walls. Moreover, the water from the smaller sections may mix back in with that from the main section.