Here are the corrections for the sentences:

1. When I looked round the door, the baby was sleeping quietly.
2. He has been ill for three weeks. He is still in hospital.
3. I'm very tired. I have driven over four hundred miles today.
4. Our friends will meet us at the airport tonight.
5. This isn't my first time to visit London. I've been here before.
6. What time did you get to work this morning?
7. When I saw him, the man was running away.
8. I haven't seen Kate since Christmas.
9. He's worked for this company for many years.
10. As soon as Martina saw the fire, she telephoned the fire department.
11. Every time Parkas sees a movie made in India, he feels homesick.
12. Since I left Venezuela six years ago, I have returned to visit friends and family several times.
13. After the race was won, the celebration began.