1. Choose the correct tense. in the correct form (comparative or superlative).

Solution:

• 1. This is the best day of my life! (Superlative form of 'good' is used to compare with all other days).
• 2. He works harder than his brother. (Comparative form of 'hard' is used to compare his effort with his brother's).
• 3. This book is more interesting than the one I read last week. (Comparative form of 'interesting' is used to compare the book with another one).
• 4. The more you practice, the better you become. (Comparative forms used to show a direct relationship between practice and improvement).
• 5. She is the tallest girl in our class. (Superlative form of 'tall' is used to compare her height with all other girls in the class).

Final Answer: 1. best, 2. harder, 3. more interesting, 4. more... better, 5. tallest