---So you think we should sell the house and move to the country.

---_______. We badly need the fresh air there.

A．Exactly.

B．Far from it.

C．Not a little.

D．No wonder.

目前，比较流行的UNIX系统属于哪一类操作系统

A．网络操作系统

B．分时操作系统

C．批处理操作系统

D．实时操作系统