Ответ:

Правило: be going to употребляется для намерения или очевидного будущего результата; will — для прогноза или уверенного решения; may — когда есть вероятность.

  1. My parents may move to a different house. They aren't sure yet.
  2. It's quite probable she'll leave school when she's sixteen. She doesn't like studying.
  3. I will never live in a different country. I love England too much.
  4. We may get flu this year. A lot of people I know have had it.
  5. I'm sure you won't go to Antarctica on holiday — you're only going to Brighton.
  6. My brother always works very hard in science. He is going to be a doctor.

Ответ: 1) may move; 2) will leave; 3) will never live; 4) may get; 5) won't go to; 6) is going to be.