题文
阅读理解 Have you ever noticed the colour of the water in a river or stream after a heavy rainfall? What do youthink caused this change in colour? It is soil that has been washed into the river from the riverbank or from the nearby fields.
Components of Soil
Soil is made up of a number of layers(层),each having its own distinctive colour and texture.The upper
layer is known as the litter.It acts like a blanket, limiting te
mperature changes and reducing water loss.The
topsoil layer is made up of small particles of rock mixed with rotten plant and animal matter cal
led humus(腐殖质),which is
black and gives the topsoil its dark colour.This layer is usually rich in nutrients,oxygen,
and water.Below the topsoil is the subsoil,a layer that contains more stones mixed with only small amounts of organic matter.This layer is lighter in colour because of the lack of humus.Beneath the soil lies a layer of bedrock.
Soil forms from the bottom up.Over time bedrock is attacked by rain, wind,frost, and snow.It is gradually broken down into smaller particles in a process called weathering.Plants begin to grow,and rotten materials enri
ch the topsoil.Most of the soil in Eastern Canada, for example, was formed from weathered rock
that was exposed when the ice disappeared 12,000 years ago.
Water Beneath the Soil
Surface water collects and flows above the ground in lakes, ponds, and rivers.once in the soil or rock,
it is called groundwater.Gravity pulls groundwater through the soil in a process called percolation(渗透).
Eventually the
water reaches a layer called the water table.Under this is bedrock through which water
cannot percolate.
As water percolates downward,it dissolves organic matter and minerals from the soil and carries them
to deeper layers.This causes a serious problem because plants require these nutrients for growth.
Soil pH
Soil can be acidic,neutral,or basic.The pH of the soil is determined by the nature of the rock from which it was formed, and by the nature of the plants that grow and rot in it.
The acidity of rain and snow can lower the pH of the groundwater that enters the soil.By burning fossil fuels such as coal,oil and gasoline,humans have been contr
ibuting to higher levels of acidity in many soils.When fossil fuels are burned, gases are released into the air and then fall back to earth as acid rain.Acid soil increases the problem of carrying nutrients to lower soil levels.As nutrients are removed,soil is less fertile.Plants grow more slowly in acidic soil,and also become easily attacked by diseases.
1. The layer of soil that provides necessary nutrients for plant growth is called ________.
A. litter
B. topsoil
C. humus
D. subsoil
2. According to the text, which of the following is NOT true?
A. Soil forms from weathered rock on the earth surface.
B. The deeper layer of soil is darker in colour than the surface soil.
C. Air pollution is partially responsible for acid soil.
D. Groundwater tends to carry away nutrients for plant growth.
3. We can infer from the passage that the water table lies ______.
A. between the topsoil layer and the subsoil layer
B. in the subsoil layer above bedrock
C. betw
een the subsoil layer and bedrock
D. in the bedrock layer beneath the subsoil
4. The underlined word "dissolve" is used to express the idea that organic matter and minerals from
soil are ________.
A. rushed away into the river
B. cleaned and purified by water
C. destroyed and carried away by water
D. mixed with water and become part of it 题型：未知难度：其他题型
答案
1-4: BBCD解析
该题暂无解析
考点
据考高分专家说，试题“阅读理解 Have you e.....”主要考查你对 [日常生活类阅读 ]考点的理解。日常生活类阅读
日常生活类阅读的概念：
日常生活这一话题主要涉及人们衣食住行等方面的活动。这一话题的选材主要针对人们日常的工作，生活以及学习情况。做这一类题时，最主要的是要把握好人物的活动内容，时间和地点。
日常生活类阅读题答题技巧：
【题型说明】
该类文章内容涉及到人们的言谈举止、生活习惯、饮食起居、服饰仪表、恋爱婚姻、消遣娱乐、节日起源、家庭生活等。文章篇幅短小，追根溯源，探索各项风俗的历史渊源，内容有趣。命题也以送分题为主，如事实细节题、语义转换题、词义猜测题和简单推理判断题等。虽然这类文章读起来感觉轻松，试题做起来比较顺手，但绝不能掉以轻心。因为稍不留神，就会丢分。
【备考提醒】
为了保证较高准确率，建议同学们做好以下几点：
1、保持正常的考试心态。笔者在教学中发现，越是容易的试题，同学们越是容易失分。为什么呢？因为在这种情况下，同学们极易产生麻痹思想，认为题目好做，就不引起高度重视，于是思维不发散、不周密。而命题人就是利用同学们的这一弱点，设计陷阱题。所以，无论试题难易与否，我们都要保持正常的考试心态。试题容易，不欣喜；试题难，不悲观。
2、根据前面讲到的方法，认认真真、细细心心做好事实细节题。
3、做好语义转换题。这类题是根据英语中一词多义和某些词语在文中能表达一定的修辞意义的原则而设计的。要求同学们解释某生词的含义，确定多义词或短语在文中的意思，确认文中的某个代词所指代的对象，或者对英语中特有的表达、格言、谚语进行解释。这种题要求同学们一定要根据上下文猜测词义或理解句子，切不可望文生义。
4、做好简单推理判断题。简单推理判断题要以表面文字为前提，以具体事实为依据进行推理，做出判断。这种推理方式比较直接，只要弄清事实，即可结合常识推断出合理的结论。
