下表是元素周期表的一部分。表中所列的字母分别代表一种化学元素。

A

B

C

D

E

N

M

Q

⑴A、B、C原子的第一电离能由小到大的顺序是__________(用元素符号表示)；

Q元素基态原子电子排布式为                             。

⑵写出BC₂^＋的电子式           ，1mol BC₂^＋中含有的π键数目为            。

⑶化合物甲由B、D两元素组成，已知甲是一种重要的结构材料，硬度大，耐磨损，晶胞如图1所示甲的晶体中B、D两种元素原子的杂化方式均为          。

⑷法国科学家阿尔贝·费尔和德国科学家彼得·格林贝格尔因在巨磁电阻效应（CMR效应）研究方面的成就而获得诺贝尔物理学奖。如图2的化合物具有CMR效应，则该化合物的化学式为                。

Networks can be interconnected by different devices. In the physical layer, networks can be connected by (11) or hubs, which just move the bits from one network to an identical network. One layer up we find bridges and switches, which operate at data link layer. They can accept (12) ,examine the MAC address, and forward the frames to a different network while doing minor protocol translation in the process. In the network layer, we have routers that can connect two networks. If two networks have (13) network layer, the router may be able to translate between the packer formats. In the transport layer we find transport gateway, which can interface between two transport connections. Finally, in the application layer, application gateways translate message (14) . As an example, gateways between Internet e-mail and X.400 e-mail must (15) the e-mail message and change various header fields.

15（）

A.analyze

B.parse

C.delete

D.create