The Sahara Desert is located in the northern part ofAfrica and covers about 9，600，000 square kilometers or32% of the continent. It is bounded in the east by the RedSea and it stretches west to the Atlantic Ocean. To thenorth， the Sahara Deserts northern boundary is theMediterranean Sea， while in the south it ends at theSahel， an area where the desert landscape transformsinto a semi-arid tropical savanna.

撒哈拉沙漠位于非洲北部，面積約960 萬平方千米，占非洲大陸的32%。它東臨紅海，向西一直延伸到大西洋，北靠地中海，往南至薩赫勒終結(jié)。在薩赫勒，沙漠景觀逐漸轉(zhuǎn)變?yōu)榘敫珊禑釒洳菰跋蟆?/p>

Since the Sahara Desert makes up 32% of the African continent， the Sahara is often cited as the worlds largest desert. This is not entirely true， however， as it is only the worlds largest hot desert. Based on the definition of a desert， as an area receiving less than 250 mm of precipitation per year， so the worlds largest desert is actually the continent of Antarctica.

由于撒哈拉沙漠占據(jù)了非洲大陸32%的面積，它常常被稱為世界上最大的沙漠。然而，這種說法并不完全準(zhǔn)確，因為它只是世界上最大的熱沙漠。根據(jù)沙漠的定義——區(qū)域年降水量不足 250毫米的地區(qū)可以稱為沙漠，所以南極洲大陸才是世界上最大的沙漠。

Although hot and extremely dry today， it is believed that the Sahara Desert has undergone various climatic shifts for the last few hundred thousand years . For example， during the last glaciation， it was larger than it is today because precipitation in the area was low. But from 8000 BC to 6000 BC，? precipitation? in the? desert increased because of the development of low pressure over ice sheets to its north. Once these ice sheets melted， however， the low pressure shifted and the northern Sahara dried out but the south continued to receive moisture due to the presence of a monsoon.

盡管如今沙漠的氣候炎熱干燥，但人們普遍認(rèn)為撒哈拉沙漠在過去的幾十萬年里經(jīng)歷了各種氣候變化。例如，在上一次冰川期，由于該區(qū)域降水量很低，它的范圍比如今的更大。但從公元前8000年到公元前6000年，由于冰原低氣壓向北部發(fā)展，沙漠的降水量增加了。然而，一旦這些冰蓋融化，低壓就會轉(zhuǎn)移，北撒哈拉地區(qū)也會干涸，但由于季風(fēng)的存在，南部地區(qū)將繼續(xù)受潮。

Most of the people living in the Sahara today do not live in cities; instead， they are nomads who move from region to regionthroughout the desert. Because of this， there are many different nationalities and languages in the region and Arabic is most widely spoken. For those who do live in cities or villages on fertile oases， crops and the mining of minerals like iron ore and copper are important industries that have allowed population to grow.

現(xiàn)在撒哈拉沙漠的居民都不是居住在城市中的，相反，他們不斷從沙漠的一個區(qū)域遷移到另一個區(qū)域，過著游牧生活。因此，該地區(qū)存在許多不同民族和語言，其中使用最廣泛的是阿拉伯語。對于那些生活在依靠綠洲建立的城市或村莊的人來說，農(nóng)作物和礦產(chǎn)，例如鐵礦石和銅礦等的開采是使人口得以增長的重要產(chǎn)業(yè)。

Word Study

stretch /stret?/ v.綿延;伸展;延續(xù)

Fields and hills stretched out as far as we could see.

precipitation /pr?'s?p?'te??n/ n.降水量（包括雨、雪、冰等）;沉淀

moisture /'m??st??r/ n.水汽;水分

nomad /'no?m?d/ n.游牧民;游牧生活