【简答题】He have missed the train; he arrived at the train station two hours early.(can't/mustn't)
【简答题】When John arrived at the station, he
found the train already gone. → , he found the train already gone.
【单选题】Why did the man get home late?
C.
The train was cancelled.
【单选题】为何咬肌、颊肌间隙感染脓肿形成时口外途径切开引流时,切口应在下颌骨下缘下1-2cm?
【单选题】带传动的功率P=10kw,速度v=15m/s,紧边拉力是松边拉力的三倍,即:F 1 =3F 2 。求:紧边拉力F1 。
【单选题】数控钻、铣、镗、磨床均属于 _____ 数控车床