[解析]
(1)D.主旨大意题.根据第二段的here are some suggestions that may help.可知作者提供了一些夜班工人如何安排好自己睡眠的建议,故选D.
(2)B.细节理解题:根据文章的第五段的Try not to vary this too much on weekends.可知作者建议平时应该保持规律的生活;故选B.
(3)C.细节理解题:根据文章最后一段的If you have tried all these things and are still having problems getting enough quality sleep during the day talk to your doctor or a sleep specialist.可知一个人如果他不能通过自己的努力得到优质睡眠应该求助于睡眠专家;故选C.