About 802.3$802\mathrm{.}3$ Ethernet, hubs and switches

($($i)$)$ Early 10$10$Mbps 802.3$802\mathrm{.}3$ Ethernet is 1−$1-$Persistant CSMA/$/$CD ($($CSMA:Carrier Sense Multiple Access, CD: Collision Detection).$).$ Briefly explain how 1−$1-$Persistant CSMA/$/$CD functions.

($($ii)$)$ Briefly explain how an 802.3$802\mathrm{.}3$ Ethernet hub that supports spanning trees operate?

($($iii)$)$ Briefly explain how the receiver MAC layer acknowledges a MAC frame sent by the sender MAC layer