Explain this Theravada Wheel of Life? Wikipedia's Bhavacakra (Within the Theravada tradition) article includes this picture of the wheel:



From inner to outer, it has four rings:


Past, Present, Future
Active and Passive
?
Twelve Nidanas


My question is, what's the third ring? Assuming I know approximately what each word in the third ring means, why are those words in particular placed in those segment of the third ring? What's the relation between the third ring and the other rings? What is the lesson or advice, how is understanding this ring useful/usable towards enlightenment?
Craving, attachment in the present lead to becoming and fabrication due to ignorance. Ignorance is included and if it is not present there is no craving and clinging to feelings hence no fabrication.

What is subjected to birth decay and death (in the future) is a being composed of the 5 aggregates due to fabrication and ignorance in the present.

Craving, clinging in the past due to ignorance hence leading to becoming and fabrication creates the rebirth, mind and matter, 6 sense bases, contact and feeling in the present.