I. complete the crossword Across 1. a long line of very big hills 4. a long turning flow of water 5. an area with a lot of trees, plants and animals 8. an area with a lot of sand, but not many plants and almost no water 9. a piece of land with water all around it Down 2. an area between two hills 3. similar to 5 across, but here it rains a lot 6. an area next to the sea with sand, where some people go to spend their holidays 7. a big, cold area that covers the land and sea around the North and South Pole