The meeting        for two hours,but they still       any agreement.

A．has been going on;haven’t reached

B．has been going on; haven’t been reached

C．was going on; haven’t reached

D．was going on; haven’t been reached

按照Internet的域名体系，域名为www.nankai.edu.cn的主机，其顶级域为（）

A.www

B.nankai

C.edu

D.cn