Fact 1: Cells vary in size as well as shape, but all cells are very small.

Fact 2: Most cells are too small to be seen without a microscope.

Given the two facts above, answer the question "Cells vary in size as well as shape and are seen with what?" with the following options: 
- Electrical energy
 - by indirect light
 - camera lenses
 - a microscope
 - a telescope
 - colors
 - bright lights
 - rays or beams


 

    a microscope     