ПОМОГИТЕ ПОЖАЛУЙСТА, 20 баллов<3
1. Transform the sentences into negative and interrogative.

By the time mum came home her son had cooked the dinner.

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

This bridge was built in 1953.

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

By the time mum came home her son had notcooked the dinner.Who had cooked the dinner by the time mum came home?Sandra had not been writing a report for three hours before she did not realize it was too late.Who  had  been writing a report for three hours before she realized it was too late?This bridge was not built in 1953.When did this bridge was built? Tom was not reading a very interesting book while his dad was not watching a football match.Who was reading a very interesting book while his dad was watching a football match?