1- Why was Dr Fridrikson helpful to Professor Lidenbrock and his nephew ?
2- Sneffels had ------------------------- .One of them was called Scartaris.
3- Why couldn't Axel persuade his uncle to give up his attempt?
4- When did the explorers become sure that the eastern passage was the wrong choice?
5- What made Axel feel stronger ?
6- What did the professor believe about scientists who think the center of the Earh is hot?