题型:选择题 —My basketball shoes are _______. —How long have you them? [ ]A. tired, borrowed B. worn out, had C. put, bought 查看答案
题型:计算题 图所示是一辆新型坦克,其质量为20t,发动机的额定功率为1000kW,每条履带与水平地面的接触面积为2m2。g取10N/kg,求:(1)坦克的重力。(2)坦克静止时对水平地面的压强;(3)坦克以额定功率行驶10min,发动机所做的功。 查看答案