11.6.4 Complete the sentences with words formed from the words in capitals. 1 The lab is protected by a fingerprint scanner and a speech system. (RECOGNISE) ) 2 Dark chocolate contains flavanoids, a type of (OXIDANT) 3 There are many different techniques to improve your memory .. . (RETAIN) 4 There is no denying the of brain research to the medical world. (USEFUL) 5 Many people use as a tool to help them achieve success. (VISUAL)​

1. For thousands of years people lived in harmony with environment and it seemed to them that natural riches were unlimited 2. Large cities with thousands of smoky industrial enterprises appear all over the world today. 3. The by-products of their activity pollute the air we breathe, the water we drink, the land we grow grain and vegetables on. Every year world industry pollutes the atmosphere with about 1000 million tons of dust and other harmful substances. 4.Many cities suffer from smog. Vast forests are cut and burn in fire. Their disappearance upsets the oxygen balance. As a result some rare species of animals, birds, fish and plants disappear forever, a number of rivers and lakes dry up. 5. The consequences of this explosion at the atomic power-station are tragic for the Ukrainian, Byelorussian and other nations. 6. As many as 159 countries — members of the UNO — have set up environmental protection agencies. Numerous conferences have been held by these agencies to discuss problems facing ecologically poor regions including the Aral Sea, the South Urals, Kuzbass, Donbass, Semipalatinsk and Chernobyl. An international environmental research centre has been set up on Lake Baikal.