Answer:
So they are lighter and move quicker.
Explanation:
With the small wings and bodies birds have it would be hard for them to escape predators and lift their own weights if their bones were dense like humans' bones. The hollow part of the birds' bone is connected to their lungs so they have enough oxygen to fly easily. Hope this can help you! :)
Answer: B
Explanation:
carbon monoxide is poison and can kill you
Plants, which had begun colonizing the land during the Silurian Period, continued to make evolutionary progress during the Devonian. Lycophytes, horsetails and ferns grew to large sizes and formed Earth's first forests. By the end of the Devonian, progymnosperms such as Archaeopteris were the first successful trees
The correct answer would be C. I hope this helps you! <3
