Ответ:

2 Have your grandparents ever seen a volcano?

3. Has Jim ever met a diver?

4. Слова пропущенны какие-то. Возможно вопрос: Have they(?) ever sailed across the ocean

5. Has a child ever climbed Mount Everest

6. Have you ever been to Australia

7. Has it ever snowed in July

8. Have you ever had an English penfriend

Ответ:

1. Have your grandparents ever seen a volcano?
2. Has Jim ever met a driver?
3. Have ? ever sailed across an ocean?
4. Has a child eve climbed Mount Everest?
5. Have you ever been to Australia?
6. Has it ever snowed in July?
7. Have you ever had English penfriend?

Объяснение:

под 3 не хватает подлежащего, наверно, оно подразумевается 1

под 7 on совершенно не нужно, возможно, имелось в виду an, которое бы стояло перед English penfriend