A. Robert Hooke
B. Louis Pasteur
C. Antonie van Leeuwenhoek
D. Robert Koch
Explanation: Antonie van Leeuwenhoek used powerful single-lens microscopes to observe microorganisms, including bacteria and protozoa.
A. Robert Hooke
B. Louis Pasteur
C. Antonie van Leeuwenhoek
D. Robert Koch
Explanation: Antonie van Leeuwenhoek used powerful single-lens microscopes to observe microorganisms, including bacteria and protozoa.