Problem: How does the sentence end?

Natalie asked Mary to help them write a song because 
Answer: Mary was an experienced songwriter.

Problem: How does the sentence end?

I drank hot chocolate rather than coffee in the evening because I thought the 
Answer: coffee would be a bad choice.

Problem: How does the sentence end?

The giant hamburger was placed into the microwave on the counter because the 
Answer: hamburger was cold.

Problem: How does the sentence end?

Craig was responsible for the bills, but Eric hadn't paid their half yet, so 
Answer:
Craig was waiting to get their half.