如图所示,电源电压为10V,R′的最大电阻值是R的3倍,滑片P在b点时电流表的示数比P在ab中点时减小了0.1A,那么R的值为( )
A:3Ω
B:9Ω
C:15Ω
D:25Ω
—Did you watch the animal show yesterday?
—No.We were to catch the last bus.
把下列十进制数化成二进制数:
(1)139(10)=____ .
(2)312(10)=____ .
(3)477(10)=____ .