Which two of the following sentences from the
article contain central ideas?

True, using a pedometer can promote a physically active lifestyle.

Ican only answer your first question, a machine is like a human body because it's a little similar. they both almost work like the same.

Whats important is to eat healthy food to prevent heart disease. another why not to get heart disease is to always exercise in a timely manner. lastly, always stay active and go to the doctor for checkups just in case.