子过程Plus完成对当前库中"教师表"的工龄字段都加1的操作。 Sub Plus( ) Dim ws As DAO.Workspace Dim db As DAO.Database Dim rs As DAO.Recordset Dim fd As DAO.Field Set db = CurrentDb() Set rs = db.OpenRecordset("教师表") Set fd = rs.Fields("工龄") Do While Not rs.EOF rs.Edit fd = fd + 1 【 】 rs.MoveNext Loop rs.Close db.Close Set rs = Nothing Set db = Nothing End Sub 程序空白处【 】应该填写的语句是( )。 A. rs.Update B. ws.Update C. fd.Update D. db.Update