孙策还没有发迹的时候,曾经向某人咨询天下大势,这个认为孙策只要抓住时机,取得的成就不会亚于齐桓、晋文。请问,这个人是谁?()
A.诸葛瑾
B.张纮
C.张昭
D.陆骏
参考答案:B
在研究微型电动机的性能时,应用如图所示的实验电路.当调节滑动变阻器R并控制电动机停止转动时,电流表和电压表的示数分别为0.50A和2.0V.重新调节R并使电动机恢复正常运转,此时电流表和电压表的示数分别为2.0A和24.0V.则这台电动机正常运转时输出功率为( )
A.47W
B.44W
C.32W
D.48W
- Why didn’t Sally play the violin at the concert last night?
- She said that her hand hurt,but that was only a(n) ____.I saw her play tennis just now.
A.excuse
B.matter
C.result
D.expression