Which of the following is true about the frequency and wavelength of electromagnetic waves? a
as frequency increases, wavelength decreases
b
as frequency increases, wavelength increases
c
frequency is constant for all wavelengths
d
frequency and wavelength are independent of each other

The controlled use of fire by hominids: (a) limited the expansion of hominids into certain environments, such as dry grasslands. (b) decreased the amount of food energy available in the hominid diet. (c) contributed to geographical expansion and food production techniques in positive ways. (d) has been shown to contribute little to the digestive process of hominids.