library的复数是libraries,而不是librarys。可数名变复数以辅音字母+y结尾的名词，变y为i再加-es。例如：baby-babies，city-cities，story-stories，party-parties，lady-ladies，diary-diaries，army-armies，century-centuries，copy-copies。而以元音字母+y结尾的是直接加-s。例如key-keys，boy-boys等。
library的复数使用举例There are many theatres, museums, and libraries in Paris.
巴黎有许多剧院、博物馆和图书馆。
Most universities offer communal access to these digital libraries.
多数大学都提供对这些数字化图书馆的公共访问。
It is difficult for a lay person to gain access to medical libraries
非业内人士难以进入医学图书馆。
The entire paper contents of all libraries will eventually be scanned into computers
所有图书馆的*纸质内容最终都会被扫描进电脑。
It seems a false economy to me to cut down on libraries.
在我看来，减少图书馆的数量并不是真正的节约。