I'm sorry, but I did the wrong exercise for homework (a)   mistake.

We decided to go (a)   bus, but we had to wait for an hour at the bus stop.

My season ticket is valid (a)   three months, so I don't have to renew it until February.

I'm tired (a)   listening to you moaning about him all the time.

You should not worry (a)   your exam results.

As the shop didn't accept credit cards, I had to pay (a)   cash.

Mary has been married (a)   John for nearly 5 years.

Carmel is very proud (a)   her daughter's achievements.

She is especially good (a)   history at school.

The little boy was very frightened (a)   the dog next door

Tom failed (a)   pass his driving test for the fourth time.