21.   Polymers generally do not conduct electricity, which is why metal wires are wrapped with plastic insulating sheaths to prevent short circuits.

22.   Scientists now are working with buckyballs to see whether they can conduct electricity without resistance or deliver medicine into the body.

23.   Semiconductors are tiny crystals that conduct electricity.

24.   Semon found that the material, PVC for short, could easily be molded and that it was waterproof and fire-resistant and would not conduct electricity.

25.   Some dust particles can conduct electricity and cause an electrical short circuit.

26.   Some of the tiny fibers can alternately conduct electricity or insulate, a basic quality of semiconducting materials.

27.   Superconductors are materials that conduct electricity without resistance, meaning there is no loss of efficiency.

28.   That is the tantalizing possibility raised by new research that shows that DNA conducts electricity.

29.   That is, it conducts electricity only when electrical or other energy applied to it exceeds a certain value.

30.   The company manufactures electrode and calcium carbide products that are used to conduct electricity and make steel.