The Sahara

The name Sahara derives from the Arabic wordfor"desert"or"steppe".At 3.5 million square miles,

an area roughly thesize of the United States,theSahara Desertin northern Africa is the largest desert inthe

world.It spans thecontinent from the Atlantic Ocean to the Red Sea.Daytime temperatures can reach as high

as 130°F.Thehumidity sometimes gets into the teens.But it can also be as low as 2.5percent,the lowest in

the world.Most ofthe Sahara receives less than five inches ofrain per year,while large areas sometimes have

no rainfall at allfor years.

At the heart of theSahara is the landlocked north African country of Niger. Here the sand dunes can be

100 feet tall andseveral miles long. Here sand plains stretch over an area larger than Germanywhere there is

neither water nortowns.Yet sitting in the midst of the surrounding desert is the town of Bilma. Suddenly there

are pools of clearwater. Surprisingly,there are groves of date palms.Underground waterresources,or oases,

sufficient tosupport irrigated agriculture are found in dry stream beds anddepressions.Irrigation ditches run

off a creek to waterfields.Corn,cassava,tea,peanuts,hot peppers,and orange,lime,and grapefruittrees grow

in thesefields.Donkeys and goats graze on green grass.

The Sahara of Nigeris still a region where you can see a camel caravan of 500 camels tied togetherin

loose lines as longas a mile,traveling toward such oasis towns.There a caravan will collectlife-sustaining

salt,which is mined fromwatery basins,and transport it up to 400 miles back to settlements on the edgesof

the desert.The roundtrip across the vast sands takes one month.

Rainfall in mostof the Sahara is_______________.

A.less than fiveinches per year

B.less than teninches per year

C.less than twentyinches per year

D.zero