【单选题】---What do you think of the waiter over there? -I don’t think he is a qualified one. He was talking __________ while taking my order.
【单选题】海上拖带时,两船长之和为280m,在拖航速度较高的情况下,拖缆长度应不小于:().
【单选题】海上拖带时,两船长之和为280m,在拖航速度较高的情况下,拖缆长度应不小()。
【单选题】一根重100N的均匀直铁棒放在水平地面上,抬起一端所需最小的力是