他 / 采摘 / 苹果 / 时 / 被 / 蜂螫 / 了 / 一下 / 手臂 / 立刻 / 肿 / 了 / 起来

他采摘苹果时被蜂螫了一下，手臂立刻肿了起来。

He was stung by a bee while picking apples, and his arm swelled up immediately.