I.
1. Who bought a new mobile? (Кто купил новый телефон?)
2. What did Jane buy? (Что Джейн купила?)
3. Did Jane buy a new mobile? (Джейн купила новый телефон?)
4. What did Jane do yesterday? (Что Джейн делала вчера?)
5. Did Jane buy her new mobile from the shopping mall? (Купила ли Джейн свой новый телефон в Торговом Центре?)
II.
1. They will play tennis at 5 o'clock in the afternoon - будущее.
2. Chinese is the most difficult language in the world - самый тяжелый, усиление.
3. They are our bad enemies. (или worst - если наихудшие враги)
4. There is a book on the table.
5. I have never driven such a big car - Present Perfect.
6. Last year the book cost $5 - Past Simple, использовано время (Last year) + 2 форма неправильного глагола cost (cost-cost-cost не меняется).
7. I ate five sandwiches and I'm not hungry.
8. He lost his keys yesterday.
9. I hope you like this new dress.
10. Granny is watering the flowers now - Present Continuous, настоящее время, к глаголу добавляется окончание -ing.