Ответ:

  1. Mum and Dad have lived in London since I was a baby.
  2. He’s been at the bus stop for half an hour.
  3. She has cooked the egg for three minutes.
  4. Our team hasn’t won since last summer.
  5. I’ve written in my diary for a week.
  6. We haven’t seen our cousins since 2007.

Правило: since употребляется с начальным моментом времени, а for — с продолжительностью.