胆总管囊肿MRCP表现是什么（）

A.胆总管杯口样梗阻

B.胆总管球形或梭形扩张

C.胆总管变细

D.胆总管偏心性狭窄

E.胆总管轻度扩张

Traditional IP packet forwarding analyzes the____(1)____IP address contained in the network layer header of each packet as the packet travels from its source to its final destination．A router analyzes the destination IP address independently at each hop in the network．Dynamic ____(2)____protocols or static configuration builds the database needed to analyze the destination IP address(the routing table)．The process of implementing traditional IP routing also is called hop—by—hop destination—based____(3)____routing．Although successful，and obviously widely deployed，certain restrictions，which have been realized for some time，exist for this method of packet forwarding that diminish its____(4)____．New techniques are therefore required to address and expand the functionality of an IP—based network infrastructure．This first chapter concentrate on identifying these restrictions and presents a rew，architecture，known as multipIeprotocol____(5)____switching，that provides solutions to some of these restrictions．

(4)

A．reliability

B．flexibility

C．stability

D．capability