Problem: How does the sentence end?

The piano that we just bought plays better than the keyboard because the 
Answer: keyboard out of tune.

Problem: How does the sentence end?

The paper that Randy wrote was worse than the paper of Christopher, since 
Answer: Christopher paper was legible.

Problem: How does the sentence end?

During recess, Mary would play in the sandbox with their friends unlike Maria because 
Answer: Mary social.

Problem: How does the sentence end?

Monica pulled up the medical image of the cancer for Megan, so 
Answer:
Monica could show details of the tumor.