Answer:D
Explanation: The pulmonary air sacs of birds only permit a unidirectional flow of air through the lungs. Unidirectional flow means that air is inhale and exhale through one trachea alternatively. This means the bird lungs only receive largely fresh air which has a high oxygen content during inhalation and do not receive fresh during exhalation. While air flow bidirectional in mammals.
Osmosis by definition is <span>movement of water from a high water concentration to a lower salt concentration.
I hope this helps.
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I think it's B: DNA replication
Answer:
everything but bacteria
Explain:
Bacteria is a type of cell as the rest are made of cells
Answer:
The ecological effects of acid rain are most clearly seen in aquatic environments, such as streams, lakes, and marshes where it can be harmful to fish and other wildlife. As it flows through the soil, acidic rain water can leach aluminum from soil clay particles and then flow into streams and lakes.
Explanation:
