单项选择题
A、正向电阻为几千欧,反相电阻为无穷大 B、正反向电阻都无穷大 C、正反向电阻都为零 D、正反向电阻都为几百欧
A、R31 B、R310 C、R3100 D、R310K
A、R³1 B、R³100 C、R³1K D、R³10K