This year the villagers have  produced _____ rice _____ they did two years ago.[ ]

A.  less ; than

B.  as less; as

C.  fewer; than

D.  as few; as

某一分光器下8个ONU用户同时全部中断，则可能的故障原因是（）。

A.皮线光缆故障

B.ONU故障

C.主干光缆断

D.数据配置故障