— How did you learn to drive?

— My father _____ me. [ ]

A. teaches

B. taught

C. is teaching

D. will teach

电子计算机供电电源B级指标为：( )。

A．稳态电压偏移范围在-5%～+5%
B．稳态频率偏移-0.2～+0.2Hz
C．电压波形畸变率5%～8%
D．允许断电持续时间4～200ms