, : present
at present
to present
to be present
1. At present, petroleum is the most important fuel and energy source.
2. Smaller amounts of sulphur, nitrogen and oxygen are present in petroleum. 3. This student presented the report on different properties of petroleum. 4. The teacher explained the Present Tense at the last lesson. 5. His present work is very important for the clear explanation of petroleum accumulation.
13. as:
as far as I know, as for me, as soon as, as a whole, as is known, as a rule, as well as, as we know, as a lubricant, as we call it.
14. - :
deep deeper (than) the deepest
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important more important (than) the most important
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good, well better (the) best
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bad, badly worse (the) worst
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many, much more (the) most
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little less (the) least
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)
15. a) :
the best method, less than a month, more than a year, as large as, not so cheap as, the worst conditions, the most interesting fact, a very important discovery, the largerthe better, far more useful system, much more steel.
) :
; ; , ; ; , ; , ; .
16. :
the highest, more, the most useful, bigger, more powerful, the cheapest, the nearest, less, the worst, the least, the best, much greater, shorter, less difficult, the most reliable.
, - .
1. Only since 19 century A.D. people have begun to use petroleum as one of the most important sources of energy. 2. Very often petroleum engineers drill deeper wells. 3. The deepest wells reach gigantic depths of 10,000 and even more metres.
4. Besides, oil often contains smaller amounts of sulphur, nitrogen and oxygen.
5. The heavier the oil the darker is the colour. 6. Oil is much lighter than water. 7. At present, petroleum is the most important fuel and energy source.
18. :
