Part A
The response that best captures why the narrator believes that it is so important for a steamboat pilot to have a good memory is:
The river is constantly changing so it is hard to navigate.
Part B
The statement from “A Cub Pilot” that best supports this answer is:
“If you will take half of the signs in that long street, and change their places once a month, and still manage to know their new positions . . . you will understand what is required of a pilot’s peerless memory.”
This statement illustrates the necessity of memory in the context of the constantly changing environment a pilot must navigate.