他们正在看电视时，停电了。
They were watching TV when the power went out.
▼点击显示答案
were英 /wɜː/|美 /wər/
watching英 /ˈwɒtʃɪŋ/|美 /ˈwɑtʃɪŋ/
解释
过去进行时 were watching 表示主事件 went out（停电）发生时正在进行的背景活动。停电是突然插入主事件，看电视是被打断的持续背景动作。
They were watching TV when the power went out.
过去进行时 were watching 表示主事件 went out（停电）发生时正在进行的背景活动。停电是突然插入主事件，看电视是被打断的持续背景动作。