Answer: (answers are in bold)
Because of the invention of the microscope, we know that all organisms are made of small living creatures called cells.
Explanation:
Well the statement explains itself; I'll explain the invention of the microscope.
No one really knows who invented the simple microscope, but the compound microscope was invented c. 1590 by Dutch lens-maker Zacharias Janssen. He used it to magnify object to about 10x their original size. Anton von Leeuwenhoek made even better ones; those had up to 275x magnification.
