They were playing basketball when the storm hit.

暴风雨来袭时他们正在打篮球。

同一单元的其他句子

• I was reading a book when the rainstorm came.暴风雨来的时候我正在看书。
• What were you doing when the rainstorm started?暴风雨开始时你在做什么？
• She was cooking dinner while it was raining heavily.下大雨的时候她正在做晚饭。
• He was sleeping when the thunder woke him up.雷声把他吵醒时他正在睡觉。
• We were watching TV when the lights went out.灯熄灭时我们正在看电视。