Hertz the distance traveled per unit of time
a unit used to express frequency of a wave; one hertz is equal to one wavelength per
second
the range of wavelengths and frequencies of electromagnetic waves
the amount of time it takes for a wavelength to pass a certain point
the number of wavelengths that passes a fixed point in a second

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms