The first option for 1 and the second option for 2
Answer:
B. Fire let humans increase their energy use tenfold
Explanation:
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Vertebrates developed about 550 million years ago. The oldest vertebrate fossils are those of FISH with no jaws. These e<span>arly jawless fish did not have paired fins and their bodies were covered with heavy, bony scaled, but their skeletons were made of cartilage. For the next 50 million years, they were the only vertebrates.</span>
Passive transport DOES NOT need energy(ATP), while active transport does.
Answer: due to insufficient exocytosis in the type II alveolar cells
