Which of these advances did Han scientists make? Select all that apply. devised the base-20 number system
developed the concept of zero
created more accurate calendars
invented the compass

so they can differentiate themselves from others as they saw themselves as the superior race. the star was basically a symbol that meant you are a less of a person than i am because of my race. the star was also degrading for those who had to wear it because they were aware of this and the nazis used the notion to make them feel less like a person.

to keep us neatruel and not get involved in any wars

he assumed control of treaty negotiations with a hostile power