Problem: How does the sentence end?

Working on the computer was perfect for Benjamin but not Kevin because 
Answer: Benjamin has a degree in programming.

Problem: How does the sentence end?

Studying philosophy was easier for Jessica than Maria, since 
Answer: Jessica had always thought long and hard about abstract concepts.

Problem: How does the sentence end?

Jason sold his new software to Brian, because 
Answer: Brian needed the services of a developer for hire.

Problem: How does the sentence end?

Nature is an important part of Eric's life but not Justin's so 
Answer:
Eric was always outside.