This question is simple. There are 23 nurses, each ward 1 1, and one person is responsible for monitoring the certificates of nurses in two wards. There are three shifts in each ward, with regular classes from 8: 00 am to12: 00 am and from 3: 00 pm to 6: 00 pm, with 4 people in the regular class. 12: 00- 15: 00, 18-23: 30, which is a shift. Night shift for 2 people (including treatment, medicine taking and dispensing 1 person, copying medical documents and writing nursing documents 1 person). 23: 30 to 8: 00, night shift. Two people take turns to rest,