Problem: How does the sentence end?

Aaron worried college was too expensive and he wouldn't be able to finish it but Matthew disagreed, 
Answer: Matthew had a hard time explaining why.

Problem: How does the sentence end?

Emily is showing Megan the appropriate method to prune flowers because 
Answer: Emily is a professional gardener.

Problem: How does the sentence end?

The music plays better on the stereo than the computer because the 
Answer: computer is quieter.

Problem: How does the sentence end?

The case was supposed to fit the firearm, but it didn't because the 
Answer:
case was too short.