Question:
The teeth of Erin were a lot dirtier than Betty's teeth, due to

Answer:
Continue the sentence -- Betty being hygienic.

Question:
Randy loved flash card memory games while Kevin hated them because

Answer:
Continue the sentence -- Randy was very good at recalling images.

Question:
Donald didn't like to keep clean the way Matthew did, so

Answer:
Continue the sentence -- Matthew tended to smell nice.

Question:
Eric could put things in the eye but not Aaron because

Answer:
Continue the sentence -- Aaron always wore glasses.