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 cn As New ADODB.Connection Dim rs As New ADODB.Recordset Dim fd As ADODB.Field Dim strConnect As String Dim strSQL As String Set cn=CurrentProject.Connection strSQL = "Select 工龄 from 教师表" rs.Open strSQL, cn, adOpenDynamic, adLockOptimistic, adCmdText Set fd = rs.Fields("工龄") Do While Not rs.EOF 【 】 rs.Update rs.MoveNext Loop rs.Close cn.Close Set rs = Nothing Set cn = Nothing End Sub 程序空白处【 】应该填写的语句是( )。 A. fd = fd + 1 B. rs = rs + 1 C. 工龄 = 工龄 + 1 D. rs.fd = rs.fd + 1