In the following essay, each blank has four choices. Choose the most suitable one from the four choices and write down in the answer sheet.
Open Shortest Path First(OSPF) is a (66) routing algorithm that (67) work done on the OSI IS-IS intradomain routing protocol. This routing, as compared to distance-vector routing, requires (68) processing power. The Dijkstra algorithm is used to calculate (69) OSPF routing table updates only take place when necessary, (70) at regular intervals.

A．but rather

B．rather too

C．rather than

D．rather that

男，61岁。乏力伴食欲减退半年余。体重下降约11kg，间断出现黑便，突然呕吐暗红色血液，量约300ml。查体：上腹部饱满，轻压痛，肝脾未触及，移动性浊音（-）。

最具有诊断意义的检查是（）

A.胃镜

B.血管造影

C.腹部B超

D.胃肠道造影

E.腹部CT