输油站要定期对备用主输泵进行盘车。盘车操作每（）进行一次。
A.天
B.周
C.月
D.季度
参考答案：B
—The old store enjoys a good reputation in this area.
—Can't agree more. There are very few, ________， complaints about their service.
A．if any
B．if so
C．if anything
D．if ever
构造湖成因景观的湖泊是：（）
A．洞庭湖
B．鄱阳湖
C．长白山天池
D．滇池
