The Sahara

　　The name Sahara derives from the Arabic word for "desert" or "steppe". At 3. 5 million square miles，an area roughly the size of the United States，the Sahara Desert in northern Africa is the largest desert in the world. lt spans the continent from the Atlantic Ocean to the Red Sea. Daytime temperatures can reach as high as 130°F. The humidity sometimes gets into the teens. But it can also be as low as 2. 5 percent，the lowest in the world. Most of the Sahara receives less than five inches of rain per year，while large areas sometimes have no rainfall at all for years.

　　At the heart of the Sahara is the landlocked north African country of Niger. Here the sand

　　dunes can be 100 feet tall and several miles long. Here sand plains stretch over an area larger than Germany where there is neither water nor towns. Yet sitting in the midst of the surrounding desert is the town of Bilma. Suddenly there are pools of cIear water. Surprisingly，there are groves of date palms. Underground water resources，or oases，sufficient to support irrigated agriculture are found in dry stream beds and depressions. Irrigation ditches run off a creek to water fields. Corn，cassava，tea，peanuts，hot peppers，and orange，lime，and grapefruit trees grow in these fields. Donkeys and goats graze on green grass.

　　The Sahara of Niger is still a region where you can see a camel caravan of 500 camels tied together in loose lines as long as a mile，traveling toward such oasis towns. There a caravan will collect life-sustaining salt，which is mined from watery basins，and transport it up to 400 miles back to settlements on the edges of the desert. The round trip across the vast sands takes one month.

　　詞匯:

　　Humidity /hju'mId ?t l/ n. 濕度 irrigate / ' lrlgelt/ v. 灌溉

　　stretch / stret?/ v. 伸展 camel /'k m ?l/ n. 駱駝

　　date palms n. 椰棗樹

　　注釋:

　　1. Underground water resources，or oases，sufficient to support irrigated agriculture are found in dry stream beds and depressions. 在干河床和洼地處可找到充足的地下水資源或者綠洲來支持灌溉農(nóng)業(yè)。

　　2. Irrigation ditches run off a creek to water fields. 灌溉溝渠通過一條小溪到達(dá)水田中。

　　3. Donkeys and goats graze on green grass. 青草上放養(yǎng)著驢和山羊。

　　練習(xí):

　　1. This passage is mostly about _______.

　　A) life in the Sahara

　　B) the deserts of Africa

　　C) Bilma

　　D) how camels travel in the desert

　　2. Rainfall in most of the Sahara is_______.

　　A) less than five inches per year

　　B) less than ten inches per year

　　C) less than twenty inches per year

　　D) zero

　　3. The Sahara can be described as_______.

　　A) a place of contrasts

　　B) a place where no one Iives

　　C) an area where the winters are cold

　　D) an area that appeals to many tourists

　　4. The phrase "an area roughly the size of the United States" gives an indication of the size of_______.

　　A) northern Africa

　　B) Niger

　　C) the Sahara

　　D) all of Africa

　　5. In this passage caravan means _______.

　　A) traveling circus

　　B) group traveling together through difficult country

　　C) railroad train

　　D) a small，fast sailing ship

　　答案與題解:

　　1. A 本題問的是:這篇文章主要講了什么?根據(jù)文段，本文主要介紹了撒哈拉沙漠的地理概 況，城鎮(zhèn)的農(nóng)業(yè)，以及城鎮(zhèn)之間的日常來往。B 選項(xiàng)范圍過寬。C 選項(xiàng)不全面，文章不止介紹了比爾馬的情況。D 選項(xiàng)文中沒有具體介紹。所以 A 是對的。

　　2. A 本題問的是:在撒哈拉的絕大多數(shù)地區(qū)，降雨情況如何?根據(jù)第一段的最后一句話，撒哈拉的絕大多數(shù)地區(qū)每年降雨量低于 5 英寸。所以 A 正確。

　　3. A 本題問的是:撒哈拉沙漠可以被描述成什么? A 的意思是，一個具有強(qiáng)烈對比的地方。B 的意思是杳無人煙的地方。C 的意思是冬天很冷的地區(qū)。D 的意思是吸引很多游客的地方。B，C，D 均不符合文意，因此 A 正確。

　　4. C 本題問的是:句子“大約和美國大小相當(dāng)?shù)牡貐^(qū)”指明的是什么地方的大小?根據(jù)第一段的第二句話可知，本句的主語是撒哈拉沙漠。因此 C 正確。

　　5. B 本題問的是:文中“caravan”的意思是什么? A 的意思是旅行馬戲團(tuán)。C 是火車。D 是又小又快的帆船。根據(jù)文中的介紹，穿過沙漠的駝隊(duì)由上百只駱駝組成，來到綠洲城鎮(zhèn)收集 鹽，因此 B 選項(xiàng)“一群人一起穿過條件惡劣的國家”是正確的。