What important anthropological discovery was made in the great rift valley?

The solstices and equinoxes, and the number of hours of daylight associated with each, are major factors in the seasons. use the drop-down menus to identify the month when each of these events occurs. the winter solstice in the northern hemisphere: an equinox in both hemispheres: the summer solstice in the northern hemisphere:

What is the border between layers a through f and layer g called?

How far is a geographic second? a.) around 100 feet b.) around 1,000 feet c.) around 5,000 feet d.) none of the above