Spontaneous recovery demonstrates that: A. learning is greater the more CS-US trials are spaced in time.
B. CS-US pairings are not necessary for classical conditioning to occur.
C. extinction does not completely erase previous learning.
D. a stimulus paired with passage of time can come to elicit a response.

and after water is usually warmed by the sun the water temperature raises and then evaporates .

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.

the elements of art are the visual tools that the artist uses to create a composition. these are line, shape, color, value, form, texture, and space.

the principles of art and design are balance, contrast, emphasis, movement, pattern, rhythm, and unity/variety.