3. Free electives: Free electives are courses in addition to the Core Curriculum and major requirements sufficient to reach a minimum of 120 credit hours for graduation. Students may graduate with more but not less than 120 credit hours.
Evaporation rates regularly exceed rainfall rates. Sometimes rain starts falling and evaporates before reaching the ground. Rainfall is lowest on the Atacama Desert of Chile, where it averages less than 1.5 cm. Some years are even rainless. Inland Sahara also receives less than 1.5 cm a year. Rainfall in American deserts is higher  almost 28 cm a year.
The Deserts of Africa - Unimaginable Beauty. Africa - the second largest continent in the world is also home to the largest desert in the world - the Sahara. In fact there are three deserts on the continent - The Sahara, the Namib and the Kalahari. Together these three amazingly vast and diverse land masses cover a large portion of Africa.