You didn't underline anything, so we cannot know for sure what the correct answer is. However, I'll just write down the entire infinitive phrases in these sentences, and you can see the answer based on that: 1. to see a great play 2. to cheer good plays 3. to practice until you know all the plays
The best preparation for a game is to practice until you know all the place. To cheer good place made by both teams is good sportsmanship. The crowd was excited to see a great play.
