What are three reasons travel was challenging for ancient greece.

An atom of element a has 73 protons. what would the element's atomic number be?

How can congress clarify parts of the constitution that are unclear?

Which is relatively better: a score of 76 on a psychology test or a score of 22 on an economics test? scores on the psychology test have a mean of 90 and a standard deviation of 13. scores on the economics test have a mean of 52 and a standard deviation of 10.