Problem: How does the sentence end?

Mary left the envelopes in the basket and focused on addressing the postcards, because the 
Answer: envelopes were nonurgent.

Problem: How does the sentence end?

Nick has a badly dislocated shoulder and asks for Robert's help, because 
Answer: Robert is doctor.

Problem: How does the sentence end?

The worker moved the cardboard from the truck to the storeroom until the 
Answer: truck was empty.

Problem: How does the sentence end?

Erin was more afraid of the Leopard Gecko crawling around than Rebecca because 
Answer:
Rebecca liked reptiles.