1. To avoid perpetual confusion between 'affect' and 'effect', the teacher advised students to memorize the typical ____ of each word.
2. If you are unsure, use a dictionary to ____ the meaning and spelling.
3. In my essay, I repeated the same word too often, so I tried to ____ it with a synonym.
4. He has corrected the wrong word in the title.
5. He will fix the wrong word in my sentence tomorrow.
6. She bought a new book about history.