I think it's 90% but I am not sure.
The correct answer to this question is this one: they lacked oxygen. The earliest organisms were completely heterotrophic in nature because of the reason that they lacked oxygen. <span>A heterotroph is an organism that cannot fix carbon and uses organic carbon for growth. </span>
Ductility is a physical property.
A physical property of a material is a property that can be measured or observed without changing the composition of the material.
In this case ductility is a physical property. It is defined as the property of a material associated with the ability to be drawn or stretched into a wire without breaking. The chemical identity of the material is not affected, that is it does not change.
Example of ductile materials include gold, silver, copper, erbium, terbium and samarium.
Other examples of physical properties are:
1. Solubility
2. Melting point.
3. Boiling point.
4. Color
5. Density.