Problem: Continue the following story.

Carrie was training Emily to be a ventriloquist, and
Here's how I want to continue it: Emily had been wanting to learn ventriloquism for a very long time.

Problem: Continue the following story.

Donald was much thinner than William was because
Here's how I want to continue it: William liked eating cake way too much.

Problem: Continue the following story.

The physical reports showed Nick was not as healthy as Ian because
Here's how I want to continue it:
Ian frequently exercised.