Question

【题目】_______ I was writing letters last night, he was watching.

A. As B. When C. While D. Before

Answer 1

【答案】C

【解析】句意：昨晚我写信时，他在（旁边）看。考查连词辨析题。A. As由于，表原因；B. When在……时候；C. While与……同时，表示动作同时发生；D. Before在……以前。本句是 时间状语从句，根据句意语境，可知主句和从句动作同时发生，故选C。