Here are the corrected sentences with the necessary apostrophes added or removed:
- The city council's decision was widely criticized for its haste and failure to let neighborhood residents speak.
- The car dealer's showroom was filled with people.
- Samson's face turned bright red with embarrassment.
- It's really nobody’s business. (Correct as is)
- Produce at a farmer's market is sometimes cheaper than at a grocery store.
- The painters' drop cloth had about 20 different paint colors on it.
- Lawrence insists this isn’t another of his publicity stunts. (Correct as is)
- The Vietnamese boat people's determination enabled many to flee from Vietnam to other countries.
- A high school in Michigan has illogically ruled that student backpacks must remain in students' lockers at all times.
- We told Katie to put on her p.j.s. (Correct as is)
- Thomas Hardy’s novels, frequently set in England’s remote countryside, often deal with the part fate plays in people's lives.
- The Senate's version of the energy bill calls for automakers to increase fuel economy in all their cars to 35 miles per gallon.
- Is it possible that Amber actually passed her driver's test?
- After exercising for several months, Armando's weight loss became obvious to everyone.
- Keisha's research paper about the UFO Museum in Göreme, Turkey, aroused everyone's curiosity.
Please note: In point 14, I corrected "Armandos" to "Armando's" and added "for" before "several months" for grammatical clarity. In point 15, it's corrected to "Keisha's" and added a proper name accent to "Göreme."