Ответ:

2a. Составляем устойчивые словосочетания:

  1. bright idea (отличная идея);
  2. open-air theatre (театр под открытым небом);
  3. cooking contest (кулинарный конкурс);
  4. strong tradition (сильная традиция);
  5. local charity (местная благотворительная организация).

2b.

  1. Throwing rice at weddings has been a(n) strong tradition in many countries around the world for ages.
  2. I’ve never been to a play in a(n) open-air theatre before.
  3. Do you think Jessica will win a prize in the cooking contest?
  4. All the money from the sales is going to a(n) local charity for people in need.
  5. Having a fancy dress party for your birthday is a very bright idea!