Which microscope did robert hooke use to study tree bark?

What are the two causes of density in deep current waters? a. salinity (how much salt) of the water and high temperaturesb. salinity (how much salt) of the water and low temperatures c. oxygen content of the water and high temperatures. d. oxygen content of the water and low temperatures

Aprocedure done under controlled conditions to test a hypothesis is an inquiry.

Fredrick griffith made a scientific discovery in 1928