Question

【题目】In the library’s warehouse, robots would manage stock and fetch books ______.

A.on boardB.on watchC.on demandD.on occasion

Answer 1

【答案】C

【解析】

考查介词短语辨析。句意：在图书馆的仓库里，机器人会管理库存和按需取书。A. on board在火车(或轮船、飞机)上； B. on watch警戒，值夜；C. on demand一经要求；承索； D. on occasion偶尔；间或；有时。根据robots would manage stock and fetch books，结合常识，可知这里意思是“按需取书”，故选C。