进口工业原料用土不需要检疫审批( )
参考答案：对
she tells him the truth now, he’ll simply keep on asking her until she does.
A．Unless
B．Once
C．If
D．Immediately
拖拉机的功率为2.85×104 W，耕地时匀速前进的速度为1m/s，则拖拉机耕地时受到的阻力为______ N，拖拉机前进100m，做功为______ J．
