Last night, before the exam, I went over the lessons I couldn’t keep my eyes ope
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Last night, before the exam, I went over the lessons_______I couldn’t keep my eyes open to stay awake any longer．
A．before B．until C．unless D．when
试题答案
B
解析:
考查状语从句。语境表示“直到我再也难以支撑的时候”，用until引导时间状语从句表示“直到……的时候”。