Answer:
i don't get it , more info ?
Explanation:
The respiratory system is the network of organs and tissues that help you breathe. It includes your airways, lungs and blood vessels. The muscles that power your lungs are also part of the respiratory system. These parts work together to move oxygen throughout the body and clean out waste gases like carbon dioxide.
Hope this help
Answer:
d) levels of nitrate pollution in local waterways
Explanation: This type of data can be expressed and measured numerically.
Answer:
A i think if not im sorry
Explanation:
The correct answer is testosterone.
A chemical messenger simply refers to a hormone.
Testosterone is a lipid - based hormone. In fact, it is an anabolic steroid . Steroids are a type of lipid which has four rings of carbon atoms.
Testosterone is a hormone produced by the Leydig's cells in the testes, and which encourages the development male sexual characteristics such as deep voice, a beard, increased muscle mass and bone mass, and growth of hair on the chest.