编辑点评： GRE写作需要大家积累一定的写作素材、锻炼自己的逻辑思维、多多积累一些有用的句子和词汇，有了这些基础以后，就需要大家根据真题来进行练习写作了。
The following appeared in a memo from the director of a large group of hospitals.
In a laboratory study of liquid antibacterial hand soaps, a concentrated solution of UltraClean produced a 40 percent greater reduction in the bacteria population than did the liquid hand soaps currently used in our hospitals. During a subsequent test of UltraClean at our hospital in Workby, that hospital reported significantly fewer cases of patient infection than did any of the other hospitals in our group. Therefore, to prevent serious patient infections, we should supply UltraClean at all hand-washing stations throughout our hospital system.
Write a response in which you examine the stated and/or unstated assumptions of the argument. Be sure to explain how the argument depends on these assumptions and what the implications are for the argument if the assumptions prove unwarranted.
中文翻译：
再一次对于抗菌洗手液的实验研究中，UC浓缩液比我们医院目前使用的洗手液多杀40%的细菌。我们对在W的医院做的随后测试中发现，该医院上报的患者感染数量明显少于我们集团的其他医院。因此，为防止严重的患者感染，我们应该在我们的医院系统内的所有洗手站提供UC洗手液。
写一篇回应，在其中检视文章的论证中述及和/或未明确述及的假设，务请解释文章的论证是如何依赖于这些假设的，并指出如果这些假设不成立会对文章的论证带来何种影响。