Archimedes. Why in the first place was the ancient Greek scientist? First of all, because he is one of the greatest mathematicians of all times, close he came to the calculation of the number of "PI". Today all students and students of the daily study and enjoy the discoveries of the Greek. Also Archimedes was famous for the invention of many useful machines. Among these are the siege guns, and mirrors, поджигающие sails on the Roman ships by focusing sunlight. Archimedes made the first theorist of mechanics. For example, he presented the complete theory of the lever, applying it in practice. Also, scientists have developed a Archimedes screw (screw), with the help of which вычерпывается water and the present day. The primacy of the inventor of merit - all of it was opened more than two thousand years ago, when there were no computers, no technology available today, the inventors. Archimedes, perhaps, he studied in the libraries of Alexandria, but most of his knowledge was acquired independently.
3) Физические свойства алюминия
Алюминий — мягкий, легкий, серебристо-белый металл с высокой тепло- и электропроводностью. Температура плавления 660°C. По распространенности в земной коре алюминий занимает 3-е место после кислорода и кремния среди всех атомов и 1-е место — среди металлов.
4)Из 4-5 тонн бокситов получается 2 тонны глинозема, из которого производят 1 тонну алюминия. В мире существуют несколько видов алюминиевых руд, но основным сырьем для производства этого металла являются именно бокситы. Это горная порода, состоящая, в основном, из оксида алюминия с примесью других минералов
Use some verbs and nouns from the previous task in the correct form to complete the sentences.
Appear, defend, repeat, apply, differ, introduce, prefer, promote.
1. I was told that these two animals differ greatly but, unfortunately, I couldn't see the difference.
2. My parents prefer to go on holidays to the sea and lie on the beach all day. My brother and I don't have the same preference.
3. Children repeat the same phrases every lesson. Teachers say that frequent repetition is the best way to learn information.
4. You can't defend yourself if you don't know anything about the self-defence.
5. He appeared so unexpectedly that nobody paid attention to his strange appearance.