前置型游梁式抽油机下冲程开始时，减速器输出扭矩（）于油井负荷扭矩。
A、超前
B、滞后
C、同时
D、不确定
参考答案：A
The art show was _____ being a failure; it was a great success.[ ]
A. far from
B. along with
C. next to
D. regardless of
矩形线圈ABCD位于通电直导线附近,如图所示,线圈和导线在同一平面内,且线圈的两个边与导线平行,下列说法正确的是:( )
A．当线圈远离导线移动时,线圈中有感应电流
B．当导线中的电流I逐渐增大或减小时,线圈中无感应电流
C．当线圈以导线为轴转动时,线圈中有感应电流
D．当线圈以CD为轴转动时,线圈中有感应电流
