A. Organic compounds - C₃N₂H₄ , C₆H₅F and C₁₂H₂₂O₁₁
Organic compounds are compounds which have Carbon except few compounds such as carbon dioxide, cyanide. Other than Carbon, other elements also present such as Hydrogen, Oxygen and Nitrogen. But Carbon is considered as the main element of organic compounds.
B. Inorganic substances - AIBr₃ , CrO₃ and <span>H</span>₂<span>O</span>₂
Inorganic substances are the compounds which do not own C-H bonds. Most inorganic compounds do not have carbon as their element except few. (Cyanides, carbon dioxide, carbon monoxide and so on are considered as inorganic although they have carbon).
The hormones are sent as chemical signals
The human respiratory system<span> is a series of organs </span>responsible<span> for taking in oxygen and expelling carbon dioxide. The primary organs of the </span>respiratory system<span> are lungs, which carry out this exchange of gases as we breathe.</span>
I believe the answer is spring