Мы тоже проходили этот текст)))
А теперь к делу.
Если это нужно сделать с любым предложениeм, то вот
1)On his journeys he doesn't meet strange see creatures and doesn't find an underwater city. - отрицание
2)Does he meet the strange see creatures and underwater city on his journeys? - общий вопрос
3) On his journeys he meets strange see creatures and finds an underwater city, doesn't he? - вопрос с хвостиком
4) Does he meet the strange see creatures and underwater city or beautiful fishs on his journeys? - альтернативный вопрос, "или-или"
5) What Does he meet on his journeys? - специальный вопрос