سؤال هام من كتاب bit by bit
 

the answer
while the telephone was ringing,we had our break fast

the telephone rang while i was having my breakfast.

while we were having our dinner thetelephon rang
while we were having our dinner the bell was ringing

أولا أنا مستغرب جدا أن الأجابات السابقة مفهاش أجابة واحدة صحيحة تماما
المهم في السؤال ده اول حاجة اننا نركز مطلوب نستخدم
While "with capital W" or " while " small w" then we will answer

While we were having our breakfast, the telephone rang. or
While having our breakfast, the phone rang

اما لو كان مطلوب استخدامها وسط الجملة هتكون الأجابة

The telephone rang while we were having our breakfast. or
The telephone rang while having our breakfast

and I'm sure that there is no more answers

I agree with you Mr.Mahmoud