The water?

12345678
Across
  1. 2. the longest river in the world
  2. 4. The biggest jungle in the world
  3. 7. The biggest country in the world
  4. 8. which sea is by Lithuania
Down
  1. 1. where will we go swimming in summer
  2. 3. the second-largest ocean
  3. 5. the longest river in Lithuania
  4. 6. the larges ocean in the world