Problem: How does the sentence end?

Emily likes to dress up for parties, while Rachel doesn't because 
Answer: Emily is a model.

Problem: How does the sentence end?

Amy had an infected wound being treated by Laura because 
Answer: Amy didn't have a first aid kit.

Problem: How does the sentence end?

In the crime scene Megan had to take the measurement of Monica's blood loss since 
Answer: Megan was the investigator.

Problem: How does the sentence end?

The teacher always yells at Katrina for sleeping in class, but not Angela. This is because 
Answer:
Katrina is the teacher's nemesis.