How can a tree grow to be 90 meters tall using only light water and air

Sufficient light, water and air allows a plant to grow and build.

Explanation:

Trees which do not grow tall get limited supply of oxygen (air), sunlight (light) and water.

Water is essential for the physical build of a plant. Plant and trees absorbs water through the root and transport it to its apex branch. Till the plant is able to do so, efficient photosynthesize activities are carried out in the presence of sunlight and water in all parts of the plant. But as tree grows taller, their upper parts do not receive sufficient water. Also, there is water loss from leaves which is not coped up. Hence, after a certain period of time drought stress is created which reduced photosynthesis and growth.  

Thus, a tree which is tall must be getting sufficient water, sunlight and air to grow.  

it also supports my hypothesis. if you rest first you can squeeze the clothespin more times. from the data i collected the average of the eight people concluded exercise makes your muscles more fatigued and less able to squeeze the clothespin compared to resting before squeezing.