A.2;50 B.2;60 C.1;50 D.1;60
A.10-6(cm/s) B.10-5(cm/s) C.10-2~10-5(cm/s) D.10-1(cm/s)
A.0.5MΩ;4Ω B.0.5MΩ;10Ω C.1MΩ;10Ω D.1MΩ;4Ω