1. were swimming / arrived
2. had / was skiing
3. Was Ian listening / asked
4. stopped / were travelling
5. Какое-то дурацкое предложение :)
Выберите сами:
weren't looking / fell off (Ты не смотрел на дорогу, когда упал с горного велика)
либо
didn't look / were falling off (Ты не посмотрел на дорогу, когда падал с горного велика)
6. Were you driving / started