题目内容
【题目】The boy was sitting under an apple tree _______ an apple fell onto his head.
A.when
B.while
C.after
D.before
【答案】A
【解析】引导表示短暂性动作的时间状语从句应用when; while表示动作或状态的延续；after和before意思不符合题意。故选A。
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题目内容
【题目】The boy was sitting under an apple tree _______ an apple fell onto his head.
A.when
B.while
C.after
D.before
【答案】A
【解析】引导表示短暂性动作的时间状语从句应用when; while表示动作或状态的延续；after和before意思不符合题意。故选A。