Problem: How does the sentence end?

Kevin found running the marathon easier than Dennis.
Answer: Kevin had finally decided to stop smoking.

Problem: How does the sentence end?

The medication made Justin sleepy but not Nelson because
Answer: Justin was susceptible to that side effect.

Problem: How does the sentence end?

The house's wood floors needed to be replaced. Rachel was asked by Rebecca for advice because
Answer: Rachel was an interior designer.

Problem: How does the sentence end?

Elena felt empathy for Samantha when they lost their favorite teddy bear, because
Answer:
Samantha was a child.