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 (36) routing algorithm that (37) work clone on the OSI IS-IS intradomain routing protocol. This routing, as compared to distance-vector routing, requires (38) processing power. The (39) algorithm is used to calculate routes. OSPF routing table updates only take place when necessary, (40) at regular intervals.

A．more

B．less

C．same

D．most

西藏蕴藏较丰富，且属于可再生的新能源是                        

A．水能、太阳能

B．太阳能、地热能

C．地热能、天然气

D．风能、煤