公路上有一排电线杆，共25根，每相邻两根间的距离是45米，现在要改成60米，可以有（ ）根不需移动。
7
—_______is the best football player in your city?
—Jerry.
A．Do you think who
B．Do you think whom
C．Who do you think
D．Whom do you think
RAID1中数据冗余是通过什么技术实现的（）。
A.OX
B.海明码校验
C.P＋Q双校验
D.镜像
