Circle the mistake (A or B), then correct it

EX3. Circle the mistake (A or B), then correct it.

1. Laura (was taking off)A her coat and (sat down)B.

1. While we (were)A on holiday, we (were spending)B most of our time sightseeing.

1. Paul (listened)A to his iPod, so he (didn’t hear)B the doorbell ring.

1. While we (were having)A a picnic, it (was starting)B to rain.

 
5. Helen was painting a picture (when)A her mum (was cooking)B