Final answer:
A pair of wool gloves is the best example of a heat insulator.
Step-by-step explanation:
The best example of a heat insulator from the given options is a pair of wool gloves. Insulators are materials that do not allow heat or electricity to easily pass through them. Wool is a natural insulator and has high thermal resistance, which helps to trap heat and keep the hands warm. In contrast, materials like glass and metal are good conductors of heat and electricity, so they are not effective heat insulators.
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