Problem: How does the sentence end?

My dog started to have a stroke, and the medicine I used didn't help because the
Answer: medicine was too weak, so I called the animal hospital.

Problem: How does the sentence end?

The sick boy's mother put his medication in some sugar to make it easier to swallow. He still had a hard time because the
Answer: medication was too strong.

Problem: How does the sentence end?

Even after only dating for three months, Christine fell in love with Erin because
Answer: Christine was very obsessive.

Problem: How does the sentence end?

Neil thought that Derrick should pay for the damage to their car, because
Answer:
Derrick was at fault.