The old man lived alone and _____ the age of 88, he _______ a cold winter morning.
A:at, passed away in
B:on, past away in
C:at, passed away on
D:on, past away on
如图所示,小灯泡L标有“2.5V 1.5W”的字样,电源电压6V保持不变,R2为定值电阻.