When Bart's vocational test reveal he should become a police officer, he improves his grades and becomes Skinner's hall monitor.
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The Simpsons Season 3 Episode 18 Quotes

Bart: Wow! Can I see your club?
Lou: It's called a baton, son.
Bart: Oh. What's it for?
Lou: We club people with it.

Dr. Pryor: Here's your scientifically selected career.
Janey: Architect.
Kid: Insurance salesman,
Ralph: Salmon gutter?
Milhouse: Military strongman.
Martin: Systems analyst. Systems analyst.
Dr. Pryor: Systems analyst.
Martin: All right!
Lisa: Homemaker?
Dr. Pryor: Mm-hm. It's like a mommy.
Bart: Police officer? Well, I'll be jiggered.