--Mike’s bike didn’t work yesterday, so he didn’t go there with his deskmate.

--He _________ mine. I wasn’t using it then.

A．need have used

B．must have used

C．could have used

D．can have used

按路由默认的优先级别从高到低的排序正确的是 (50) 。

A．直接路由、静态路由、rip、ospf

B．直接路由、ospf、静态路由、rip

C．直接路由、ospf、rip、静态路由

D．直接路由、rip、静态路由、ospf