65. Changeable shape2. We know that an element is organic because it is formed by carbon.
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67. Low-density polyethylene is more flexible than high-density polyethyleneTHERE ARE MORE THAN THOSE POSSIBILITIES 5. High-density polyethylene is made by petroleum.
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69. 10. Polyvinyl chloride is derived from sodium chloride and petroleum. 11. Write some principal uses of the polyvinyl chloride are: Construction, Films, Jars, Blisters, Plugs… 12. Which are the four types of polystyrene? PS crystal, Polystyrene of high place in the environment, Expanded polystyrene and Polystyrene extrudate. 13. Some properties of polystyrene are… (Choose the correct answers). a)It can float in the water d) It hasn’t got resistance to high temperatures