Micasso, I think the thing your photos are missing is emotion. You've got a waterfall, some leaves and brush, a tree, a monkey's butt, and some signs, none of which leave a person feeling anything when they look at the photos.
There's a huge difference between capturing an image and capturing a moment. Anyone can go around and take photos of objects, but it takes someone with a good photographic eye to be able to pull emotion from plain old objects and convey that to an audience. For instance, look at your photo from Everest - what emotion do you feel looking at that? I really don't feel anything. But had you composed it with the rollercoaster (out of focus) in the background it would have made more of an impact.
You need to be more creative with your camera angles, your depth of field, and your exposure to add something.
Some things to keep in mind for next time:
Subject - When you compose your shot you need to think "what am I capturing here?" If you look at your first photo there's really no subject, nothing to draw your eye to.
Lighting - Your photos appear to be taken during mid-day. The lighting is really harsh at this time. In the picture of the Africa sign you can see how the partial shade, partial sun is very distracting. A better time to snap photos is just before sunset. Everything will have a nice, soft glow to it without any shadows. You can also see how washed out your Tree of Life photo was from too much sunlight.
Composition - Look at your photos from the Animal Kingdom entrance. The bottom of the elephant is cut off and then the top half of the photo is nothing but plain blue sky. Try to compose your shots to fill the frame a little better.
Focus - Make sure the subject of your photo is the thing in focus. In your photo of the monkey, it would have been a much better photo if the monkey's face was in focus instead of its butt. Another tip when photographing living things or statues of living things - you HAVE to get at least 1 of their eyes in the photo. The eyes should almost always be the thing in sharp focus. When someone's eyes aren't in focus or someone's eyes aren't in the photo it can be very distracting.
Depth of field - Try and use a more narrow depth of field in your photos so that only your subjects are in focus and the rest is blurred. (You do this by standing back and zooming in). Depth of field will make your photos feel more "3D" instead of so flat.
Hope that helps. Keep on trying! The more you do it, the more of an eye you'll get for it if you're passionate about it.