【名词&注释】
文件系统(file system)、数据交换(data exchange)、数据模型(data model)、单元测试(unit test)、主要特征(main features)、软件工程实践(software engineering practice)、数据通信。、数据链路层(data link layer)、第二层交换机(the second layer exchange machine)、第三层交换机(layer 3 switches)
[单选题]In developing a hospital database, it is determined that on the average, each patient will have 6 treatments during a hospital stay.The average length of a stay is three days.The hospital has 1000 beds.There are on the average 800 patients occupying beds each day.The relationship between PATIENT and TREATMENT is 1: M.The relationship between PATIENT and BED is 1:1, conditional.If treatment record occurrences are archived as soon as a patient is discarded from the hospital, how many occurrences of the TREATMENT records will be stored in the TREATMENT database file on the average?
A. 6,000
B. 4,800
C. 18,000
D. 1,600