Where does a clinical trial usually take place? O A. In a hospital
B. In a test tube
c. In a placebo
D. In a petri dish

Witch type of microscope is used to view very small cell components like proteins and dna?

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

Which is not a characteristic of bacteria? a. they are unicellular. b. they are prokaryotic. c. they are the smallest form of life on earth. d. they are multicellular.