The Professor tell Harry to C: look for the water.
Explanation:
‘Journey to the center of the earth’ by ‘Jules Verne’ is a science fiction story. It is about a great scientist “Professor Lidenbrock” who is a lecturer at “Hamburg University”.
Harry was a young boy who came to stay with the professor as his parents had died. He was like an assistant to the great scientist. Professor decided to go to the center of the earth, but Harry was always unsure about the trip the professor had planned. They were out of water, so the professor asked Harry to look for water.
I think the structure is cause and effect. They choose to put the titles this way so the reader will have an idea about what they are reading. And lastly “Top Food Chain”