translate the sentences into negative and interrogative. by the time mum

By the time mum came home her con didin't had cooked the dinner.  

Did by the time mum came home her con had cooked the dinner?

Sandra didn't had been writing a report for three hours before she realized it was too late.  

Did Sandra had been writing a report for three hours before she realized it was too late?

This bridge didn't was built in 1953.  

Did This bridge was built in 1953?

Tom was reading a very interesting book while his dad didn't was watching a football match.

Did Tom was reading a very interesting book while his dad was watching a football match?