I think ---
1. Relative Size<span>2. Texture Gradient</span>
Answer:
D
Explanation:
Alternative energy is best defined as the use of energy sources other than traditional fossil fuels, which are considered environmentally harmful and are in short supply. Fossil fuels consist of natural gas, coal, and oil. Currently, fossil fuels are the most used energy source to heat our homes and power our cars.
<span>Birds
Birds are organisms which utilize a one-way air flow through their lungs to maximize air flow efficiency and oxygen consumption
The process of respiration is essential in the oxygen/carbon dioxide cycle. Respiration removes OXYGEN from the atmosphere and produces and releases CARBON DIOXIDE to the atmosphere.answer is letter D.
Respiration driven by a mechanical series called inhalation and exhalation. We inhale or breathe in oxygen and exhale or breathe out carbon dioxide.
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