1、I am writing this letter in the purpose of rendering some suggestions to improve the quality of your service.

【译文】我写这封信是为提高贵方服务质量提供几条建议。

【分析】此句常用于建议信的开头部分，开门见山地向收信人表明写作目的是想就某一问题提出观点或建议。句中 in the purpose o￡ 可以替换为 with the intention of；整个句子也可以替换为I am writing this letter to render/give some suggestions to…或者 I'm writing to tell some of my ideas/express my views on how to...。

2、Firstly, it will be better to arrange an inquiry desk at the circulation hall so that students could go through the procedures more efficiently.

【译文】首先，最好在循环大厅安排一个咨询台，以便同学们能更迅速地完成这些程序。

【分析】It will be better to…是一种委婉表达建议的说法，就前文提出的问题表达个人建议。其他类似的委婉表达建议的说法还有 It will be beneficial/helpful/profitable to/if…。