Answer:
Hominids
*Appeared 3 to 4 million years ago in souther and eastern Africa.
*Humanlike creatures called primates
*Mary and Louis Leakey excavated hominid fossils in the Great Rift Valley
*"Lucy," and Australopithecine fossil, found in 1974.
*Three major differences from earlier primates: bipedalism (gives ability to walk upright), a sizable brain (enables abstract thought and fine motor control), and a larynx (allows for complex speech)
*Thought-processing ability led to alteration of the natural environment to suit human needs
A theory is a well tested explanation that can be replicated.
A hypothesis is just an educated guess that can be proven or falsified.
And a law is something that can be universalized (universal).
Answer:
a longer wavelength means a lower frequency, and a shorter wavelength means a higher frequency!
Caring for another person very deeply