Problem: How does the sentence end?

Robert wanted to swim in the hot tub at Benjamin's house, but 
Answer: Benjamin was gone.

Problem: How does the sentence end?

Sarah was pulled over by Cynthia who was a police officer because 
Answer: Cynthia caught them speeding.

Problem: How does the sentence end?

The student knew basic math from the book, though he was confused my the problems on the board, because the 
Answer: board had advanced equations.

Problem: How does the sentence end?

Because Derrick paid for an expensive dinner for Justin on their date that did not go well, 
Answer:
Justin felt guilty.