Question

【题目】Deserts are found where there is little rainfall or where rain for a whole year falls in only a few weeks' time. Ten inches of rain may be enough for many plants to survive if the rain is spread throughout the year. If it falls within one or two months and the rest of the year is dry, those plants may die and a desert may form.

Sand begins as tiny pieces of rock that get smaller and smaller as wind and weather wear them down. Sand dunes (沙丘) are formed as winds move the sand across the desert. Bit by bit, the dunes grow over the years, always moving with the winds and changing the shape. Most of them are only a few feet tall, but they can grow to be several hundred feet high.

There is, however, much more to a desert than sand. In the deserts of the southwestern United States, cliffs (悬崖) and deep valleys were formed from thick mud that once lay under a sea more than millions of years ago. Over the centuries, the water dried up. Wind, sand, rain, heat and cold all wore away at the remaining rocks. The faces of the desert mountains are always changing –-very, very slowly ---as these forces of nature continue to work on the rock.

Most deserts have a surprising variety of life. There are plants, animals and insects that have adapted to life in the desert. During the heat of the day a visitor may see very few signs of living things, but as the air begins to cool in the evening, the desert comes to life. As the sun begins to rise again in the sky, the desert once again becomes quiet and lonely.

【1】Many plants may survive in deserts when___________.

A. it is dry all the year round

B. the rain falls only in a few weeks

C. there is little rain in a year

D. the rain is spread out in a year

【2】Sand dunes are formed when____________.

A. sand piles up little by little

B. there is plenty of rain in a year

C. the sea has dried up over the years

D. pieces of rock get smaller

【3】The underlined sentence in the third paragraph probably means that in a desert there is_____.

A. too much sand

B. more sand than before

C. nothing except sand

D. something else besides sand

【4】It can be learned from the text that in a desert____________.

A. there is no rainfall throughout the year

B. life exists in rough conditions

C. all sand dunes are a few feet high

D. rocks are worn away only by wind and heat

Answer 1

【答案】

【1】D

【2】A

【小题3】D

【4】B

【解析】

试题分析：文章介绍了沙漠的有关知识。沙漠主要宣传于降水稀少或全年降水集中在几周内的地方。风力等外力的作用使岩石变成了沙子，在风力的作用下，沙子堆积成沙丘。沙漠里不只有沙子，悬崖和深谷也是沙漠里的景象。当然，沙漠里也是有生命存在的，它们多在夜间活动。

【1】D段落大意题。根据首段“...many plants to survive if the rain is spread throughout the year”可知，如果雨水分布于全年而不是集中在一两个月的话，很多植物就可以在沙漠里生存。全年干旱的话，许多植物无法存活，排除A；根据第一句中的“Deserts are found ...where rain for a whole year falls in only a few weeks' time”可知，降水集中在几周内的地方常形成沙漠，排除B；根据“Deserts are found where there is little rainfall”可知，降水很少的地方往往形成沙漠，排除C；故选D。

【2】A细节理解题。根据第二段“Sand dunes (沙丘) are formed as winds move the sand across the desert. Bit by bit, the dunes grow over the years,”可知，沙丘形成于风力作用，风携带沙子在沙漠中移动，沙子逐渐堆积成沙丘；根据第三段可知，C项是悬崖和山谷形成的原因；根据“Sand begins as tiny pieces of rock that get smaller and smaller”可知，D项是沙子形成的原因，故选A。

【小题3】D猜测句意题。根据“cliffs (悬崖) and deep valleys were formed from thick mud”可知，沙漠里不止有沙子，还有悬崖和很深的山谷，说明划线句的意思是“沙漠里不止有沙子，还有其它的事物”，故选D。

【4】B推理判断题。根据首段首句“Deserts are found where there is little rainfall or where rain for a whole year falls in only a few weeks' time.”可知，沙漠里也会有降水，但是降水很少或降水不均，排除A；根据第二段“Most of them are only a few feet tall, but they can grow to be several hundred feet high.”可知，大部分的沙丘只有几英尺高，但并不是全部的沙丘都是高几英尺，排除C；根据第三段“Wind, sand, rain, heat and cold all wore away at the remaining rocks.”可知，对岩石起作用的不仅是风力和热量，还有雨水、沙子和热胀冷缩，排除D；根据最后一段可知，沙漠里有生命存在，并且它们多在夜间活动，故选B。