Explanation:
The discoveries indicates that the rocks were formed over millions of years ago due to the age of fossils they contain. 
Fossils are the preserved remains of life found in rocks. Most fossils are used in relative dating of rocks. 
- Dinosaurs are extinct organisms that once lived in the Mesozoic. This was about 100 million years ago. 
 - Tool man also grazed the surface of the earth just a few thousands to a million years.
 - We are able to find their fossils in rocks because they have lived in some certain geologic periods. 
 - Here we are using the fossils to date the rock and this is called relative dating 
 
learn more: 
Fossils brainly.com/question/7382392
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Answer:
I think it's the second one or first one 
 
        
             
        
        
        
Answer:
Explanation:
Immunity to a disease is achieved through the presence of antibodies to that disease in a person's system. Antibodies are proteins produced by the body to neutralize or destroy toxins or disease-carrying organisms. Antibodies are disease-specific. Viruses make us sick by killing cells or disrupting cell function. Our bodies often respond with fever (heat inactivates many viruses), the secretion of a chemical called interferon (which blocks viruses from reproducing), or by marshaling the immune system's antibodies and other cells to target the invader. A vaccine works by training the immune system to recognize and combat pathogens, either viruses or bacteria. To do this, certain molecules from the pathogen must be introduced into the body to trigger an immune response.
These molecules are called antigens, and they are present on all viruses and bacteria.  
 
        
             
        
        
        
B is correct
D is appealing but the electrons spend more time around the oxygen than the hydrogen
        
             
        
        
        
 The alveoli needs of the epithelium for the gaseous exchange and stratified squamous epithelium are formed of multiple layers the difficulty in a gaseous exchange