依据《传染病防治法》的规定，各级各类医疗保健机构在传染病防治方面的职责是（）

A.对传染病防治工作实施统一监督管理

B.按照专业分工承担责任范围内的传染病监测管理工作

C.承担责任范围内的传染病防治工作

D.领导所辖区域传染病防治工作

E.设立专人负责各施工区域的卫生防疫工作

An internet is a combination of networks connected by （1）. When a datagram goes from a source to a （2）, it will probably pass many （3） until it reaches the routerattached to the destination network. A router receives a （4）from a network and passes it toanother network. A router is usually attached to several networks. When it receives a packet, towhich network should it pass the packet The decision is based on optimization: Which of theavailable（5） is the optimum pathway

（1）是（）

A.modems

B.routers

C.switcher

D.computers