问题
选择题
下列简单机械中，属于费力杠杆的是（ ）
A．羊角锤
B．钓鱼杆
C．定滑轮
D．钢丝钳
答案
A、羊角锤在使用过程中，动力臂大于阻力臂，是省力杠杆；
B、钓鱼杆在使用过程中，动力臂小于阻力臂，是费力杠杆；
C、定滑轮在使用过程中，动力臂等于阻力臂，是等臂杠杆；
D、钢丝钳在使用过程中，动力臂大于阻力臂，是省力杠杆．
故选B．
搜题请搜索小程序“爱下问搜题”
下列简单机械中，属于费力杠杆的是（ ）
A．羊角锤
B．钓鱼杆
C．定滑轮
D．钢丝钳
A、羊角锤在使用过程中，动力臂大于阻力臂，是省力杠杆；
B、钓鱼杆在使用过程中，动力臂小于阻力臂，是费力杠杆；
C、定滑轮在使用过程中，动力臂等于阻力臂，是等臂杠杆；
D、钢丝钳在使用过程中，动力臂大于阻力臂，是省力杠杆．
故选B．
On Sundays, Li Lei gets up at six thirty. He has at eight. Then he helps his mother the housework（家务劳动）. At ten o’clock he leaves and goes shopping bike. At about eleven o’clock he comes home. He likes very much. He helps his mother with the cooking. They lunch at twelve. In the afternoon he often games with his friends. They have at six thirty. In the evening he does his homework. Sometimes, he TV. He goes to bed at nine.
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