Possible Clues:

• How vet works internally to survive in ship?
• Opportunities for school keeps the wolves from the door
• Teacher in the "Monkey Trial"
• Keep one's head above water in ship watching over the guns
• Sizes or ranges of subject or topics covered
• ''Inherit the Wind'' inspiration
• Sharpshooters' magnifiers
• ___ out (evaluates)
• "Monkey Trial" teacher
• Famous US science teacher's optical instruments