Поставьте предложения в косвенную речь.
Tom asked his friends, «Have you ever been in Australia?».
«I like travelling by plane», she said.
«We visited Russia last winter», they said.
«I’ll be in Brighton next weekend», Mary said.

Правильный вариант в косвенной речи:

1. Tom asked his friends if they had ever been to Australia.
   Здесь общий вопрос Have you ever been...? превращается в косвенный вопрос с if/whether, а Present Perfect меняется на Past Perfect:
   have been → had been.

2. She said that she liked travelling by plane.
   Present Simple меняется на Past Simple:
   like → liked.
   Местоимение I меняется на she.

3. They said that they had visited Russia the previous winter.
   Past Simple меняется на Past Perfect:
   visited → had visited.
   last winter меняется на the previous winter.

4. Mary said that she would be in Brighton the following weekend.
   will меняется на would:
   I’ll be → she would be.
   next weekend меняется на the following weekend.