Help: One Question for each: Linked List and Tree

1. This is about linked list.

I know how to dump the elements of a linked list to the screen in a First-In-Last-Out manner.

However, how can I do it in a First-In-First-Out manner?

Should I change the way of adding element (i.e. by adding elements at the tail of list rather than the front of the list)?

Or should I change the way of dumping elements to the screen?

2. This is about tree. I know how to dump the elements of a tree in "alphabetical manner".

However, how can do it in a First-In-First-Out manner?

Should I change the way of adding elements (which seems to violate the priciple of making a tree)?

Or should I change the way of dumping elements to the screen?

3. Is there any other methods (or other types of dynamic data structure) which serve the above purposes with higher efficiency?

First in First out. Look into .Stacks