Ex 1. Read the dialogue and reproduce it a) abridged; b) in the form of a monologue.
| Prof. Smirnov: Student: Prof. Smirnov: Student: Prof. Smirnov: Student: Prof. Smirnov: | Today we are going to consider the following questions: erosion, weathering (chemical and mechanical weathering). Will you explain what the term erosion means? All the processes by which rocks are worn down and by which the debris is carried away are included in the general term erosion. There exists one more term gradation. You learnt about it at the previous seminar. Yes, we know that the leveling of landscape by erosion is often referred to as gradation. During our practice we saw the rough, pitted surfaces of old stone monuments and buildings. Such sort of disintegration brought about by rainwater and atmospheric gases is called weathering. But what are the active erosional agents? Weathering is in part a chemical process, in part a mechanical process. It participates in erosion in an important way by preparing rock material for easy removal by the more active erosional agents. Among the agents whose work is most obvious are streams, glaciers, wind and waves. Less apparent is the erosional work of groundwater, water in crevices and channels beneath the surface. Id like to know whether you have got any information concerning chemical weathering. What is easily attacked by chemical weathering? Some of the minerals in igneous and metamorphic rocks are especially susceptible to chemical weathering. most sedimentary rocks, on the other hand, consist of rock debris that has already undergone chemical weathering, and so are relatively resistant to further attack; the chief exception is limestone. As for mechanical weathering the most effective process of mechanical disintegration that does not involve chemical action is the freezing of water in crevices, since water expands when it turns into ice and considerable forces can be developed in this way. Plant roots aid in rock disintegration by growing and enlarging themselves in cracks. In conclusion Id like to say that the upper part of the weathered layer, in which rocks debris is mixed with decaying vegetable matter, is the soil. And from a human point of view the formation of soil is the most important result of weathering. |
Ex 2. Translate into English using the vocabulary of the dramatized dialogue.
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Listening Comprehension
Text Continental drift
Part A. Pre-listening activities
Task 1. Make sure that you know the following words and word phrases.
float v ( )
hard a
involve v
plate tectonics
rigid a
occur v
consequence n
stiff a ,
flow n
outermost a
shell n , ,
soft a
distinguish v
speed n
apply v
respond v
Task 2. Before listening answer the following questions?
1. What were Pangaea and Panthalassa?
2. What explanation was the accepted one before Wegeners theory?
3. What evidence did Wegener have for this theory?
4. Into what did Pangaea begin to break apart later?
5. Was continental drift taking place even before Panagea was formed?
6. Which supercontinent did your country once belong to?
Part B. Listening Activities
Task 1. As you listen to the tape make brief notes to help you answer the following questions.
1. What questions will be looked at in this lecture?
2. What for is the term continental drift used?
3. Why didnt most people believe Wegener was right until the nineteen sixties?
4. What idea does the lecturer consider to be absolutely central?
5. What do we call lithosphere?
Task 2. Listen to the tape once more and
A) fill in the gaps.
1. Wegener thought the continents freely over the mantle.
2. The ocean floors are actually extremely.
3. Plate tectonics sees the continents as passengers on a number of .
4. These rigid rock plates continually the face of the earth.
5. The crust the earth is a completely structure.
