Answer:
An understanding of biology can help you make choices and decisions that affect your health. Biologists and other scientists research environmental issues such as pollution, biodiversity,land conservation, and natural resource use. 
Explanation:
Hope this helped Mark BRAINLIEST!!!
 
        
             
        
        
        
Answer:
Petroleum gas is mainly C3 and C4 based (propane and butane), whilst natural gas is predominantly C1 and C2 (methane and ethane). Petroleum gas is generally produced via the cracking of naphtha, which is one of the components separated during crude oil refining.
Explanation:
 
        
             
        
        
        
The correct answer is B, internal intercostal muscles and abdominal muscles would contract. 
Exhalation is the flow of the breath out of the body. During forced exhalation, internal intercostal muscles contracts which lower the rib cage and decrease thoracic volume, while the abdominal muscles push up on the diaphragm which causes the thoracic cavity to contract. 
        
                    
             
        
        
        
Its 3 of the same molecule.
        
             
        
        
        
B is the correct answer because all the classes are hierarchy’s in a sense