The hollow<span> part of a </span>bird bone<span> isn't wasted space. In some </span>bones<span>, the </span>hollow<span> cavities contain extensions of the air sacs from the lungs. These air sacs help the </span>bird<span> to get the oxygen it needs to fly quickly and easily.</span>
Answer:
nuclear energy
Explanation:
An atom has a nucleus (or core) containing protons and neutrons, which is surrounded by electrons. Protons carry a positive electrical charge, and electrons carry a negative electrical charge. Neutrons do not have an electrical charge.
<em>For example,</em>
<em> consider a mountain whose summit is 5,000 feet (1,500 m) in elevation, but somewhere on the way up, the trail goes back down 250 feet (76 m). ... </em>
<em>If one hikes over five hills of 100 vertical feet each, the cumulative elevation gain is 5 × (100 feet (30 m)) = 500 feet (150 m).</em>
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I think it's B: DNA replication
The answer is los automoviles
