Dear Sir or Madam,As a regular library user, I would like to express my sincere gratitude to you for the help you render me.

尊敬的先生或女士，作为贵馆的读者，我想对您给予的帮助致以诚挚的谢意。

I am writing the letter in purpose of offering some conducive recommendations to upgrade the quality of your service.

我写这封信的目的是提出一些有益的建议来提升您的服务质量。

Firstly, a great many students express their frustration with our library in that there are usually long lines waiting for assistance,

首先，由于等候帮助时总要排很长的队，很多学生表达了他们的不满。

Secondly, since computers are used by all major libraries to streamline cataloguing,

其次，由于所有大型图书馆都使用电脑来简化检索，

we should have access to the Internet via computers.

我们应该讲电脑接通互联网。

Lastly, I shall be much obliged to you if you could kindly replace all the outdated facilities and provide more conveniences to readers.

最后，如果您能好心地替换所有过时的设备并为读者提供更多的便利，我将十分感谢。

I hope you will find the proposals practical.

希望这些建议对您有所帮助，

Your prompt attention to my suggestions would be highly appreciated.

非常感谢您及时关注这些建议。

Yours sincerely, Li Ming

您真诚的，李明