— Do you know anything about the school?

— Yes. In fact, this is the third time I _____ here. [ ]

A. was

B. came

C. have been

D. will come

若每一条指令都可以分解为取指、分析和执行三步。已知取指时间t 取指＝4△t，分析时间t分析＝3△t，执行时间t 执行＝5△t。如果按串行方式执行完100 条指令需要（4）△t。如果按照流水线方式执行，执行完100 条指令需要（5） △t。

A．1190

B．1195

C．1200

D．1205