This Mac's MAC ID's .....

= The ID of the MAC belonging to this Mac is ....

This Mac's MAC's broken.

= The MAC belonging to this Mac is broken.

This Mac's MAC's RJ45 socket's loose.

= The socket belonging to the MAC belonging to this Mac is loose.

There are 35 Macs in this lab. All of these Macs have MACs installed, but none of the Macs' MACs are working. It may be an issue with this model MAC's Mac drivers, or the Mac's generic MAC drivers, installed by default in all of these Macs. These Macs' sysadmin is Tom Ferbelknapfkopfel; these Macs are all under his control. It's likely that these Macs're on their way out the door anyway; if that's the case this here Mac'll be going home with me.

Contraction of "is": apostrophe

Belonging, possession: apostrophe

Plural: NO apostrophe

Plural possession: apostrophe ~after~ plural "s" (because no-one writes or says "Macs's" or "Macse's"; that would be silly)

Capiçe?