Choices: (I) Refract it. (II) refraction of light. (III) an electron lens. (IV) an image. (V) rays or beams. (VI) bending light rays. (VII) A computer. (VIII) flashlights.

Fact 1: Viruses are so small that they can be seen only with an electron microscope. Fact 2: On the surface of each microscopic color filter is also a microscopic lens. Given the two facts above, viruses are so small that to see them a scientist would have to use what kind of lens?
Answer:
(III)