翻译是：
You had better not speak/talk loudly in the reading room
句型had better do sth：最好干某事
speak/talk：说 in the reading room：在阅览室里
英语翻译：你最好不要在阅览室里大声说话.（had better）
翻译是：
You had better not speak/talk loudly in the reading room
句型had better do sth：最好干某事
speak/talk：说 in the reading room：在阅览室里