Here’s how the sentences can be matched to the point, evidence, and analysis:
Point: The writer presents crossword puzzles as both a form of entertainment and a mental exercise.
Evidence: The writer says that crossword puzzles can help to keep your memory "razor sharp."
Analysis: By using the metaphor "razor sharp", the writer creates an image of a sharp blade, which emphasises the idea that by doing puzzles regularly, your memory will become both a powerful instrument at your disposal and as finely tuned as a razor blade.