Describe the state of development of the vertebrae, spinal column and rib cage of humans at time of birth. Explain how this is adaptive

At the time of birth, much of the skeleton in this area is formed by a cartilaginous, soft, flexible and short-bone material. Evolutionarily this characteristic is adaptive because it allows folding inside the uterus and easy to leave at the time of delivery.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

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