孔子学院是中国派驻外国推广中国文化的教育机构，目前全球100多个国家和地区已经建立了

关于氯己定溶液，下列哪项叙述错误

A．它是一种广谱抗菌剂
B．使用浓度为0.12%～0.2%
C．长期使用会使牙面、舌背着色
D．化学结构稳定、毒性小
E．主要缺点为长期使用可形成耐药菌株或造成人体损害

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

老山前线英雄（）所作的《血染的风采》是一个不错的道德演讲。

A.邱少云

B.黄继光

C.徐良

D.雷锋

相关方举例（）：（）.

用液态二氧化碳或氮气做动力，将灭火器内的灭火剂喷出来进行灭火的灭火器是（）灭火器。

A.泡沫

B.二氧化碳

C.1211

D.干粉