山东液压数控冲床:trip off the tongue什么意思？？？

trip off the tongue什么意思？？？ off-the-shelf 是什么意思 组句子;trip,air,relaxing,was,the why do people trip to the countryside? Turn off the shoes. 是什么意思? He fell off the ladder. off-the-cuff 如何翻译? commercial-off-the-shelf是什么意思？ keep off the premises是什么意思？ take the day off 怎么说