Question

【题目】The two experts worked at the task of writing a preface to the new dictionary for three hours__________.

A.at length B. on end C.in full D.in time

Answer 1

【答案】B

【解析】考查介词短语辨析。句意：这两位专家连续工作了三个小时为新词典写前言。on end＂连续地，不断地＂，符合句意。at length＂最后，详尽地＂；in full＂全部＂；in time＂及时＂。