Write in the correct word:

For thousands of years, stone, wood, and animal skin had been the basic materials used by ancient civilisations for house building, ship construction or producing elementary tools. However, the first synthetic products which _ P _ _ _ _ _ D (1) in the 19th century were _ _ _ _ F _ _ _ _ _ _ D (2) of cellulose and very quickly gained _ R _ _ _ _ (3) replacing their heavy, less durable and antiquated counterparts. The commercial success of celluloids has become even more conspicuous in the 20th century as dozens of new _ _ P _ _ _ _ _ _ _ _ S (4) for plastic goods have been invented. Nowadays, life without celluloid dishes, synthetic furniture and garments as well as other manifold polimeric products would be UN_ _ _ _ _ N_ _ _ _ (5). What makes them so favoured and common a merchandise are their exceptional _ T _ _ _ _ _ _ _ S (6).