Problem: How does the sentence end?

Donald had never taken typing lessons, while Kevin had, so 
Answer: Donald was slower at transcribing documents.

Problem: How does the sentence end?

I tried to fit the paper under the door, but it wouldn't go because the 
Answer: door was too tight.

Problem: How does the sentence end?

The pool party was held at Justin's house and not Aaron's because 
Answer: Justin pool was bigger.

Problem: How does the sentence end?

Joel purchases more nuts and seeds at the grocery store than Eric because 
Answer:
Eric doesn't own a pet squirrel.