[Q]: How does the sentence end?

Adam used crystals instead of modern medicines to heal his wounds because he believed the 
OPTIONS:
- crystals to be less effective.
- modern medicines to be less effective.

[A]: modern medicines to be less effective.
QUES: Continue writing.

Elena was a worse overall tennis player than Mary however 

OPTIONS:
- Elena had a great serve.
- Mary had a great serve.
+++++++++
ANS: Elena had a great serve.
Problem: How does the sentence end?

The room was too stuffy for the businessman so he moved to the hallway, since the 
OPTIONS:
- room was a pleasant environment.
- hallway was a pleasant environment.
Answer: hallway was a pleasant environment.
sentence: Betty loved the scent of the coconut shampoo Mary bought, so  OPTIONS:
- Betty told her where she could buy some of her own.
- Mary told her where she could buy some of her own.
complete: Mary told her where she could buy some of her own.
Cynthia had to buy an extra freezer but not Tanya because 
OPTIONS:
- Cynthia liked to eat frozen food.
- Tanya liked to eat frozen food.
Cynthia liked to eat frozen food.
Problem: Continue the following story.

Derrick enjoyed going to school more than Christopher because 
OPTIONS:
- Derrick was never prepared for class.
- Christopher was never prepared for class.
Here's how I want to continue it:
Christopher was never prepared for class.