Theboywassittingunderanappletree       anapplefellontoh...

問題詳情：

The boy was sitting under an apple tree        an apple fell onto his head.

A. when             B. while                    C. after

【回答】

A。引導表示短暫*動作的時間狀語從句應用when; while表示動作或狀態的延續；after意思不符合題意。故選A。

知識點：連詞

題型：選擇題