部分容积效应伪影的一般表现是（）

A.影像中出现同中心的圆

B.影像的中心部分出现指压样伪影

C.骨与软组织边缘出现条纹状伪影

D.物体的边缘出现星晕样伪影

E.整个影像模糊

One of the most widely used routing protocols in IP networks is the Routing Information Protocol (RIP)．RIP is the canonical example of a routing protocol built on the (1) algorithm．Routing protocols in internet works differ slightly from the idealized graph model．In an internet work，the goal of the routers to forward (2) to various networks．

Routers running RIP send their advertisement about cost every (3) seconds．A router also sends an update message whenever an update from another router causes it to change its routing table．

Routing protocols use different techniques for assigning (4) to individual networks．Further, each routing protocol forms a metric aggregation in a different way．RIP takes the simplest approach，with all link costs being equal (5) ．Thus it always tries to find the minimum hop route．Valid distances are 1 through 15．This also limits RIP to runing on fairly small networks．

1（）

A．Dijkstra

B．path-vector

C．link-state

D．distance-vector