Вставьте необходимые предлоги.
1) Chlorofluorocarbons are released … the daily use of industrial and household products.
2) Deforestation could cause one forth of all species on earth to vanish … the next 25 years.
3) United Nations Environment Program (UNEP) concentrates its activities … these issues.
4) We are obliged to remove factories and plants … cities.
5) These are the main practical measures, which must he taken … order to improve the ecological situation.