Large quantities of solid fuel ______consumed every day and too much carbon dioxide is sent into the air, which in turn _______ the going up of temperature.   [ ]

A. is; results in  

B. are; results in  

C. is; leads to  

D. are; results from

按照通信距离或覆盖范围，计算机网络可以分为( )。

A．局域网

B．城域网

C．广域网

D．无线网