Correct the mistakes in the underlined parts. Write the correct verb forms.

1. Tom had been training for three years when he took part in the competition. 2. This scientist had made a few discoveries by the time he died. 3. Pete hadn’t played tennis before, so Chris showed him what to do. 4. Brian and Sue were cooking when their son came from school. 5. Victor had been working at the train station for 5 years when he was made a manager. 6. Sandra was out of breath because she had been jogging.