A:①②③④
B:④②③①
C:②④①③
D:④①②③
一节新的干电池的电压为____ 伏,教室里电风扇正常工作时的电压为____ 伏,每个电风扇之间是____ (选填“串联”或“并联”)连接的。通过一个导体的电流为0.3安,它表示的物理意义是____ 。
____ oke
____ ____playing soccer this afternoon?
A stupid man tells a woman to shut up, while a wise man tells her that her mouth is quite beautiful _______ it is closed.