OSPF is a link-state routing protocol. It is designed to be run internal to a single (1) system. Each OSPF router maintains an identical(2) describing the autonomous system's topology. From this database, a routing table is calculated by constructing a shortest-path (3).OSPF recalculates routes quickly in the face of topological changes, utilizing aminimum of routing (4) traffic. OSPF provides support for equal-cost multipath. An area routing capability is provided, enabling.an additional level of routing protection and a reduction in routing protocol (5).

空白（2）处应选择（）

A.tree

B.table

C.database

D.record

任何单位和个人购买商业银行股份总额( )以上的，应当事先经国务院银行业监督管理机构批准。

A．3%

B．5%

C．8%

D．10%