.---- The presidents of China and the USA had ___interview a short time ago.

---- And it was __great success.

A．an; /

B．the; a

C．an; a

D．the; /

典型的Ethernet交换机端口支持10Mbps与l00Mbps两种速率,它采用的是【 】

A．并发连接技术

B．速率变换技术

C．自动侦测技术

D．轮询控制技术