Other than Native Americans, who else arrived in America before the Europeans

The corresponding time unit is the mean solar day dm. With the aid of clocks, dm is further divided into 24 hours of 60 minutes, each minute being in turn divided into 60 seconds. The definition of the duration of the second as the 86400th part of the mean solar day basically was arbitrary, and part of our tradition.

either b) they were often feared and despised by other native cultures. or

c) their obsession allowed them to coexist with many other native cultures because of their peaceful nature.