Problem: How does the sentence end?

I decided to travel around the world by plane instead of train because the
Answer: plane is faster.

Problem: How does the sentence end?

Erin wanted to go to a bar to celebrate the team's victory, but Christine wanted to go home, because
Answer: Christine was feeling exhausted.

Problem: How does the sentence end?

Logan spent days organising the event that Justin was going to attend, because
Answer: Justin was a conference participant.

Problem: How does the sentence end?

Natalie was less prepared for the talent show than Kayla because
Answer:
Natalie studied very lazily.