Problem: How does the sentence end?

Erin had roofing installed for Christine's apartment yesterday because 
Answer: Christine was the tenant of the apartment.

Problem: How does the sentence end?

Megan got into more trouble than Mary got into because the friends of 
Answer: Mary were saints.

Problem: How does the sentence end?

Matthew was helping Leslie download a new security update on their computer for 
Answer: Leslie forgot how.

Problem: How does the sentence end?

The man couldn't decide on a smoothie or a milkshake. He decided on a 
Answer:
milkshake because it is creamier.