Problem: How does the sentence end?

Because Ryan had a lower metabolism than Joel 
Answer: Joel was able to lose weight more easily.

Problem: How does the sentence end?

Hunter didn't get the flu this year, but William did because 
Answer: Hunter got his flu shot.

Problem: How does the sentence end?

The woman tried to use the small comb to brush her hair but the 
Answer: hair was too strong.

Problem: How does the sentence end?

Robert has always struggled with sobriety, but Craig doesn't have that issue. 
Answer:
Robert is an alcoholic.