1. Steven hasn't come home yet. (Present perfect, из-за слова YET)
2. I haven't seen Tom for a week (present perfect. со словами FOR SINCE perfect времена употребляютя)
1.
1. China. 2. Russian. 3. French. 4. Spain. 5. German. 6. England. 7. Polish. 8. Italian. 9. Japanece. 10. Turkey.
2.
1e, 2i, 3g, 4h, 5f, 6d, 7b, 8c, 9a.
Tall taller the tallest
Old older the oldest