Odd One Out, redux

I started a forum game called Odd One Out way back in 2009, and it seemed to be mildly successful in its time. I figured I'd try it again!

The rules, shortened quote from the original topic's post:

I post a list of three or more items.
Then the next three people to post pick an item and give a short explanation of why they think that item is unique from the others.
(Note that two or more people can pick the same item, as long as they give different explanations.)
I then pick the person whose explanation I like the best, and that person posts a list. Repeat.

So, as I also said in that post, it's kind of like Apples to Apples: you appeal to the judge if possible.

I'll start:
Earth, Wind, Fire, Water

Wind. Its the only force that is there, but isn't there. Wind is air moving, and without moving air there is no wind. You cannot see wind, but you know it is there.

Earth, because it is also the name of a Planet on the Solar system.

Fire. It's the only one that hurts you every time you touch it.

Heyo! I got three replies. I was honestly a little worried.

I like Polana's answer the best! So Polana wins. Your turn~

No one made an Earth, Wind & Fire reference? Dang, that seemed right up this forum's alley. Oh well.

My turn ?
Well...
Train, tram, bus, trolley bus.

Train, because it's not related to a bus.

Train, because I like riding on trains! (even though the ticket prices just went up.  )

Train because its usually ment to transfer long distances, where a tram, bus and trolley bus usually are short distances.

Bus because it doesn't begin with a T...?

Train because it's the only one what can transport load such as coil, etc.?

Okay, it's Sergio.
I had another explanation of why is it bus. This one is so simple I even did not think about it, but I like it most of them.

Train, because I like riding on trains! (even though the ticket prices just went up.  )

Me too. 

Owl, moth, snake, wolf.

Snake, because it has no legs.

Wolf, only hairy one.