Which property of the water cycle makes it a good illustration of the conservation of matter?
a. water absorbs energy and then releases it later on.
b. the water cycle is constantly repeating on earth's surface.
c. water changes form, but the total amount of water remains the same.
d. the water cycle includes many different steps, and each step involves matter.

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.