М. М. Кутепова The World of Chemistry Мир

Read the text thoroughly with a dictionary and answer the following questions:

1. 
   How did all living matter appear?
   
2. 
   What is the objective of evolution?
   
3. 
   What four elements are essential for biosphere?
   
4. 
   What are the roles of sulphur and phosphorus in the biosphere?
   
5. 
   What changes must the biologically important materials undergo?
   

3. 
   Entitle each paragraph of the text, write out the sentence(s) expressing the main idea(s) of each of them and translate these sentences into Russian.
   
4. 
   Write a summary and an abstract to the text.
   
5. 
   Revise grammar and lexical material to Units 8 and 9 and translate the following sentences into Russian:
   

1. 
   Not only is man replacing the Earth’s major ecosystems with cities and land devoted to agriculture, but leakage of toxic substances from man-dominated provinces of the Earth is reducing the structure and self-regulation of the remaining natural ecosystems.
   
2. 
   Important as these conditions for the existence of a biosphere may be in terms of historical evolution, it is not the history that we are concerned with now but rather what the future developments are likely to be.
   
3. 
   It would seem not unlikely that we are approaching a crisis comparable¹ to the one that occurred when free oxygen began to accumulate in the atmosphere.
   

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4. 
   Presumably, if we do want to continue living in the biosphere, we must introduce unprecedented processes.
   
5. 
   It is the industrial fixation of nitrogen that far exceeds all the others in magnitude.
   
6. 
   We do know that excessive run-off nitrogen compounds in streams and rivers can result in “blooms” of algae and intensified biological activity that deplete the available oxygen and destroy fish and other oxygen-dependent organisms, the process known today as eutrophication.
   
7. 
   Different as the world might become from the present one, there is no reason a priori why it would be necessarily unpleasant.
   

6.