A) OVER A BIG WATERFALL
The characters were going over a big waterfall. The water was driving them quickly. They landed but soon they rushed up again in a chimney. The Professor asked for food and knew that nearly all their food was lost.
B) IN THE MIDDLE OF AN ACTIVEVOLCANO
Around them, the water was boiling, the rocks were burning and the needle of the compass was going in all directions. They were in the middle of an active volcano.
The raft was spinning around in circles. Red-hot lava and flames were around them. Axel fainted because of the heat around him.
When Axel opened his eyes, he saw the sky. They were back on the surface of the Earth