the photograph shows a consequence of air pollution. which of these was most likely the cause of the effect shown in the photograph?

I’d say a : water molecules

From our previous experiment, we examined how many drops a penny can hold - and place drops of salt water on the penny after recording 5 trials each, take the average of each solution.

Ican't see the images : ( 

Ithink most frequently occurring lab-acquired infection. proper way to clean up a small blood spill that has dried on surface are to be used when caring for all patients at all times. which of the following actions would violate a lab safety rule.