Ответ:

1. You are always losing - your sunglasses!
2. I lose weight - when I eat less sugar.
3. The train to Manchester is leaving - right now. Hurry up!
4. My son, Jimmy, has - lunch at school every day.
5. Fresh-cut apples don't change their colour - if sprinkled with lemon juice.
6. The train to Manchester leaves - at 6:30 a.m. on Sundays.
7. Melvin is having - lunch now.
8. This chameleon is changing its colour - just look at it!