BTS日常维护中进行告警与性能监控的网管巡视周期为（）
A.1次/2小时
B.1次/3小时
C.1次/4小时
D.1次/5小时
参考答案：C
(2013·高考陕西卷)Marco Polo is said to have sailed on________Pacific Ocean on his way to Java in________thirteenth century.
A．the；a
B．a；不填
C．不填；the
D．the；the
