为了合理组织数据，应遵循的设计原则是

A．"一事一地"的原则，即一个表描述一个实体或实体之间的一种联系

B．用外部关键字保证有关联的表之间的联系

C．表中的字段必须是原始数据和基本数据元素，并避免在表之间出现重复字段

D．以上各原则都包括

Multiple users are trying to telnet to the AIX server. They are able to ping the server successfully， but are  getting  the  following  error  message：  telnet：  connect：  A remote  host  refused  an  attempted  connect   operation Which of the following options could be the cause of this problem（）

A、The routing table on the AIX server is incorrect.

B、The IP address in the /etc/hosts file is incorrect，

C、The portmap daemon is not running on the AIX server.

D、The inetd daemon is not running on the AIX server.

（）是随着数据通信业务发展而迅速发展起来的一种新型接入Internet方式，主要适合集团企业对带宽要求比较高的应用。

Where does Layer2 de-encapsulation occur on the ERX Edge Router？（）

A、on the SRP

B、on the I/O adapter

C、on the egress line module

D、on the ingress line module

A user is connected on a DSL line and is using a PPP over Ethernet service.Which network device strips the ATM header from the datagram and investigates the PPP header?（）

A、DSLAM

B、DSL modem

C、ERX Edge Router

D、customer workstation

An AIX server will not boot in normal mode and the server must be booted into maintenance  mode to rebuild the boot logical volume. A NIM master is not defined in this environment.  How is the system booted into maintenance mode to perform this task （）

A、Apply power and when the SMS menus appear press 5 repeatedly to enter a maintenance boot automatically. The system will present a maintenance shell eventually.

B、Boot media such as CDROM or Tape is required to boot into maintenance mode. When inserted into the proper device the system automatically boots into maintenance mode when it can not boot into normal mode.

C、Apply power and the server automatically boots into maintenance mode where you can select your disk to rebuild the boot logical volume.

D、Boot media such as CDROM or Tape is required and an administrator must select the proper SMS menus to get into maintenance mode.