Problem: How does the sentence end?

Tanya brought the jicama they had grown to Victoria, because 
Answer: Tanya was a good gardener.

Problem: How does the sentence end?

Logan evaluated the condition of Kyle to make sure they were ok, since 
Answer: Logan was a doctor.

Problem: How does the sentence end?

Donald helped create the strange and intricate statue for Ryan's garden since 
Answer: Donald was the artist who made it.

Problem: How does the sentence end?

Joseph helped Donald with writing his historical fiction book because 
Answer:
Donald was less experienced in the field.