Your nose and your mouth are both a portal of entry into your body. If you cover one and not the other it defeats the purpose because Bacteria can still enter the system. They are both part of your respiratory system. 
 
        
             
        
        
        
D- Biosphere
 The part of the earth and its atmosphere in which living organisms exist or that is capable of supporting life
        
             
        
        
        
Answer:
b . chemical weathering
Explanation:
Chemical weathering is not affected the flow of groundwater through an aquifer but affect by the porosity and permeability. The rate of groundwater flow is controlled by two properties of the rock which are porosity and permeability. Porosity is the percentage of void space in a rock while on the other hand, Permeability is the quality of being permeable means able to be penetrated or passed through by a liquid or gas.
 
        
             
        
        
        
Used by American pioneers living in the Great Plains in the 19th century. The emigrants traveled by wagon in search of fertile land in Oregon's Willamette Valley.
        
             
        
        
        
9. Normal tides would remain the same but neap and spring tide cycle would be cut in half. Meaning if there was a neap tide after every 14 days it would come 2 times faster (after every 7 days)