Explain why the several different types of microscopes are all necessary.

quoted, but you can learn from this.

Explanation:

"The different types of microscopes are all necessary because not all experiments require the same level of magnification. [ For dissections low magnification is sufficient, so a dissecting microscope works very well, while for viewing single cells the 1000 fold magnification of a compound light microscope is more than adequate. ] "

it is the most commonly accepted one