2. What are the most important things you have learned in this unit about how the trillions of cells in the human body get what they need to function, and what they do with the things they absorb?

frogs. the lower the ph the higher the acid content. frogs have the highest tolerance in this scenario.

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.

i would think a oil tanker that has leaked in a bay