Answer:
Most animals/some plants
Explanation:
Organisms that have to get or eat food are organisms that can't produce ATP without injesting chemical energy (most animals/some plants).
Ostrich eggshell is composed of 96% crystalline calcite and 4% organic material, mostly proteins. The thickness is made up of three different layers that vary in structure and thickness. The hardness of the shell is 3 on the Mohs scale. Pretty solid!
