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Read the following text and think of the word which best fits each gap. Use only one word in each gap. There is an example at the beginning (00).

Mechanical Weathering

Ramsey, W.L., Burckley, R.A. Modern Earth Science. – USA: Holt, Rinehart and Winston, Inc., 1965.

The effects … weathering may be seen wherever rock is exposed. of
Small chips of rocks may be loose or easily pulled off … surface.  
Some of these may crumble … a touch.  
When the rock is broken with tools, the inner parts are found … be firm  
and may be different … colour from the surface.  
In cracks and crevices, however, air and water have been … to penetrate.  
Some rocks are broken down … small pieces  
without undergoing any changes … mineral composition.  
One of the most important means of mechanical weathering … temperature.  
Low temperatures cause water to freeze and are responsible … much of the mechanical weathering.  
When water freezes, it expands by about 10 percent of … volume.  
If water seeps into cracks in rock and then freezes, the pressure exerted by its expansion is capable … splitting the rock.  
Another process of mechanical weathering causes thin flakes to peel … the exposed rock surfaces.  
Exfoliation was once thought to … caused by strains produced in the rocks as a result of unequal expansion between the outer surface and the interior.  
Temperature changes from day … night were thought to produce this.  
It has been observed, …, that exfoliation is most common in humid climates and not in the deserts.  
This has led … the conclusion that exfoliation is caused by the combination of temperature changes  
and the expansion … certain minerals in the rock.  
These minerals expand as they combine chemically with water which seeps into the rock … tiny cracks.  

For questions 1-15, read the text below and decide which answer (A, B, C or D) best fits each gap. There is an example at the beginning (0).

0 AerosionBcorrosionCoxidationDrust

A B C D

Erosion

Wikipedia, the free encyclopedia

(0) …is the (1) … by which material is removed from a region of the Earth's surface. It can occur by weathering and transport of (2) … (sediment, soil, rock and other particles) in the natural environment, and leads to the deposition of these materials elsewhere. It usually occurs (3) … to transport by wind, water, or ice; by down-slope creep of soil and other material under the force of (4) …; or by living organisms, such as burrowing animals, in the case of bioerosion.



Land that is used for industrial agriculture generally experiences a significantly greater rate of erosion than that of land under natural vegetation, or land used for sustainable agricultural practices. This is particularly true if (5) …is used, which reduces vegetation cover on the surface of the soil and disturbs (6) … soil structure and plant roots that would otherwise hold the soil in place.

Erosion is distinguished from weathering, which is the process of chemical or physical breakdown of the minerals in the rocks. The two processes may occur (7) …, however. The rate of erosion depends (8) … many factors. Climatic factors include the amount and intensity of precipitation, the average temperature, as (9) … as the typical temperature range, and seasonality, the wind speed, storm frequency. The geologic factors include the sediment or rock type, its porosity and permeability, the slope (gradient) of the land, and whether the rocks are tilted, faulted, folded, or weathered. The biological factors include ground cover from vegetation or lack thereof, the type of organisms inhabiting the area, and the land use.

In general, given similar vegetation and ecosystems, areas with high-intensity precipitation, more frequent rainfall, more wind, or more storms are expected (10) … more erosion. Sediment with high sand or silt contents and areas with steep slopes erode more easily, than (11) … areas with highly fractured or weathered rock. Porosity and permeability of the sediment or rock (12) … the speed with which the water can percolate into the ground. If the water moves underground, less runoff is generated, reducing the amount of surface erosion. Sediments containing more clay tend to erode less than those with sand or silt. Here, however, the impact of atmospheric sodium on erodibility of clay should (13) ….

Roads are especially likely (14) ... increased rates of erosion because, in addition to removing ground cover, they can significantly change drainage patterns, especially if an embankment has been made to support the road. A road that has a lot of rock and one that is "hydrologically invisible" (that gets the water off the road as quickly as possible, mimicking natural drainage patterns) has the best chance of not (15) … increased erosion.

A event B incident C process D occasion
A liquids B gases C fumes D solids
A as a result B due C on account D because
A inclination B impulse C burden D gravity
A handling B manufacturing C tillage D refinement
A either B both C and D or
A separately B distinctly C singly D concurrently
A on B in C at D of
A good B well C bad D badly
A to have B have C having D having had
A are B do C be D have
A confect B infect C effect D affect
A be considered B to be considered C to consider D consider
A cause B to cause C causing D have caused
A cause B to cause C causing D have caused

 

8.2.9. A. Work in two teams. You are members of a conference committee. You are going to organize a conference on the topic “The Power of Wind, Heat, Water, and Organic Matter in Shaping the World: Natural Hazards and Disaster Preventing Techniques.” As a group make a list of research problems to be discussed within different workshops. Issue an information bulletin containing a brief summary of all the workshop discussion points to attract prospective participants.

B. Exchange information bulletin with the other team. Select the problem you are most interested in to take part in the conference held by your partners. Make a short report. Keep to a limit of 3-5 minutes.

 


Date: 2015-12-11; view: 1218


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