常用来描述计算机的运算速度的指标是( )。 A: A) MIPS B: B) MHz C: C) Mbits D: D) MBytes

【单选题】97:The difference between the mobile ISDN and MPDS isthat A. the mobile ISDN is charged by connection time and MPDS is charged by lVlbits transferred B. the mobile ISDN is charged by Mbits transferred and MPDS is charged by connection time C. there is no difference between the mobile ISDN and MPDS D. the communication fee of the mobile ISDN is inexpensive than that of MPDS