Final answer:
Thermoplastic polymers can be heated until they liquefy, applied to a surface, and allowed to cool to form a solid again.
Step-by-step explanation:
Thermoplastic polymers can be heated until they liquefy, applied to a surface, and allowed to cool to form a solid again. This process can be repeated multiple times. Examples of thermoplastics include polyethylene and polypropylene. They can be molded when heated and solidify when cooled.