4. At the conclusion of experiments involving growing bacterial cultures, should be added to the plates or tubes and everything should be soaked for .

Disinfectants should be added to the plates or tube and everything should be soaked for 4–10 minutes.

Explanation:

Disinfectants are suitable in the destruction of bacteria microorganisms on a motionless surface. Disinfectants are commonly used in hospitals and other places which human beings have great contact with.

one would be wind another would be water density

i think the answer is b.