— What should I do before operating the new machine?— You’d better read its first careful

问题补充：

— What should I do before operating the new machine?

— You’d better read its first carefully.

A. explanations

B. instructions

C. descriptions

D. introductions

答案：

A. explanations

(答案→)B. instructions

C. descriptions

D. introductions

解析：本题考查名词的词义辨析。explanations“解释，说明”；instructions“说明，指南”；descriptions“描绘，描写”；introductions“介绍，前言”。所以，根据句意应选B。

等。k+s-5#u