1. explain the full nature of the high plans aquifer. what is it, how it might have formed what recharges it, and its physical and chemical makeup.

2. describe what is going on geologically and tectonically in great lakes tectonic zone. to do this, you must discuss the history of what occurred and how it relates to what is happening today.

This is all you, but i can give you some topics that you could try. if it rained when you want to do something outdoors, it 'limits' that human activity. maybe you want to do an experiment that goes throughout the whole year and you have to have above freezing the entire year. this 'limits' your activity. i thought of those just off of the top of my head. something that gets to me that might be getting to you is you are thinking too hard about what to do. think simply, and if it is too simple, then bump it up just a little bit.

Tropical climate is experienced in the nothern countries of south america

Anstobacco uses;  

Granite is a hard stone and lasts for a long time in both modern and ancient buildings. as proof of its durability, granite is often used in gravestones and memorials, intended to last for many years.