问题描述: The o____ of the new machine is hard to learn____填什么? 1个回答 分类:英语 2014-11-17 问题解答: 我来补答 The operation of a new machine can be hard to learn.operation:[ ˌɔpə'reiʃən ] n.手术,行动,活动,操作 展开全文阅读