下列哪项发明推动了东汉冶铁技术的进步[ ]
A、
B、
C、
D、
答案：A
Statistics show that men have _____ as women do for every mile they drive. [ ]
A. serious accidents as twice many
B. twice as many serious accidents
C. twice serious accidents as many
D. serious accidents as many twice
A．当单刀双掷开关与a连接时，电压表的示数为22V
B．当单刀双掷开关与b连接时，电压表的示数为11V
C．当单刀双掷开关与a连接，滑动变阻器触头P向上移动的过程中，电压表的示数不变，电流表的示数变大
D．单刀掷开关由a扳向b时（滑动变阻器触头P不动），电压表和电流表的示数均变大
sin
V