The total volume of the gas-exchanging region in the lung is called alveolar volume.
The alveolus is an air sack-like organ in the end of the respiratory airway. The alveolus is the site where gas-exchanging happens, so only air inside alveolus that will undergo actual exchange. Air in bronchus or trachea wouldn't do exchange
Answer: D. Add water features to private gardens.
Renewable resources are those which can be replenished after one or subsequent uses. Examples include oxygen, fresh water, solar energy and biomass. Adding water features to private gardens can be a mode of replenishing freshwater. A system which can absorb the water which is being supplied to plants in the garden through soil and collect this water as a reservoir in the form of groundwater.
The answer is hard determinists
The answer is a. the troposphere