hand cancel at post office是什么意思

hand cancel at post office是什么意思 cancel cancel “at hand,in hand,on hand,by hand”分别是什么意思? 英语翻译Generally,there are two possible ways of active vibration cancellation,the Inertial massshakers,attached at suitable points,cancel out the disturbing vibration by a force signal ofopposite phase.On the other hand,active engine mounts comp 用at hand造句 at the hand of post ,situation ,position,place.employment,profession,occupation区别He asked me to lend him a hand,but i was not in a -----to help him at that time.A post B.situation C.position ..D.place ..为什么呢? at hand,by hand,in hand,on hand,to hand ,with hand at the finishing post是什么意思? in hand at hand on hand 分别是虾米意思. 求问in/hand,at/hand,on/hand各是什么意思? at hand,in hand,on hand,by 简要,各造句, at post office 和in the post office一样吗? He asked me to lend him a hand,but I was not in a __ to help him at that time.A.post B.situation C.position D.place in hand,on hand ,at hand,off hand有什么区别? Post post