She------(listen) to the English program when I went to see

was listening ①when意为"在……时刻或时期",它可兼指"时间点"与"时间段",所引导的从句的动词既可以是终止性动词,也可是持续性动词。如：When I got home,he was having supper。我到家时,他正在吃饭。When I was young,I liked dancing。我年轻时喜欢跳舞。②while只指"时间段",不指"时间点",从句的动词只限于持续性动词。如：While I slept,a thief broke in。在我睡觉时,盗贼闯了进来。辨析 ①when从句与主句动作先后发生时,不能与while互换。如：When he has finished his work,he takes a short rest。每当他做完工作后,总要稍稍休息一下。(when = after) When I got to the cinema,the film had already begun。当我到电影院时,电影已经开始了。(when=before) ②when从句动词为终止性动词时,不能由while替换。如：When he came yesterday,we were playing basketball。昨天他来时,我们正在打篮球。③当从句的谓语是表动作的延续性动词时,when,while才有可能互相替代。如：While / When we were still laughing,the teacher came in。正当我们仍在大声嬉笑时,老师进来了。