Rock 2- volume=30cm3, mass=60g, and density=2g/cm3
Mold is a living organism, therefore it is biotic.
sludge
<span>Sewage treatment is also known as wastewater treatment. It is
a process whereby contaminant is removed from wastewater. Thus, chemical,
biological and physical process are commonly used to remove contaminants from
wastewater and the by-products of wastewater treatment is usually inform of
solid waste known as sewage sludge.</span>
Answer:
The grasshopper doesn't have to use it circulatory system to carry gases to and from the grasshopper cells because the air that is passed through the trachea system is already close enough to get to the cells.
Explanation:
"In the grasshopper, exchange of oxygen and carbon dioxide occurs in the tracheal system. Hemolymph plays no part in the process. There is not even an oxygen-carrying pigment in insect hemolymph." - www.biology-pages.info
(Here's some extra info as well)
