I was watching TV while my father was sleeping.
当我爸在睡觉的时候，我在看电视。
I picked up the phone when it rang.
电话响起时，我接起来了。
He called while/when I was sleeping.
我在睡觉时他打来了。(这里用while或when都可以)
I got into an accident while I was driving home.
我开车回家时发生意外了。
I was sleeping when he called.
他打来时我在睡觉。
