While后面加过去进行时的例句如下：
While he was eating，I asked him to lend me $2.当他正在吃饭时，我请他借给我二美元。
While I was reading，she sang.我看书时，她在唱歌。
While it was raining，the electricity went out.下雨的时候停电了。
The electricity came back on while we were sleeping.我们睡觉时又有电了。
While Ken was calling the police，the neighbor's dog was barking.当肯在给警方打电话时，邻居的狗在犬叫。
比如，my father is watching TV while my mother is cooking.
