What are some of physical concerns williams discusses when considering a trip to mars?

The physical concerns of Williams discuss when considering trip to Mars are: First, a person would feel light headed because of the environment in the outer space compared to what we have on Earth. Second, the heart will be able to adapt in terms to the micro-gravity. Lastly, there will be a possibility of the bones of a human will lose its own density.

i think its c. amphipod

the dna of humans and mice is almost 92% similar. this similarity indicates that . mice have a tail, while humans have a tailbone. the tailbone is a structure in humans.yes it's true.