22. A close relationship between two species that benefit at least one of
the species is called
a. Natural selection
b. Symbiosis
O
c. Adaptation
D. Competition

The anwser is: wave a has a greater pitch and frequency.

The chemical reactions lab we did is typically called a "copper plating lab,  because the acid solution cleaned the pennies and made the copper look shinier;   the acid solution cleaned the paperclips and made them look like pennies;   &   the copper from the pennies was removed, and then added to the paperclips.