Answer:
I think it is the excretory system
Nuclear Membrane
The nuclear membrane is a double layer that encloses the cell's nucleus, where the chromosomes reside
They are all rock with different size and shapes and are located in different areas possibly in the same areas but they all have there own unique textures from the photographs and 3 of them look like maybe a fossil of some type of when the dinosaurs where still around and the rocks on the top left corner look smooth and are a small type of igneous rocks. That have been soothed over the years.
The one with higher air pressure is Warm Air. The reason why is because when you boil water, the water always makes the lid rise. This is because Warm Air has more activity in its atoms and molecules, so it is moving around more, which in turn means that there is more pressure.
Hope I helped. :)