Healthy bones, teeth, and muscles require the mineral?
carbon
sodium
calcium
cadmium
iron

Individuals do not compete directly for resources, but are prey for the same predator

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.

According the inverse square law, doubling the distance from the source of the sound, a speaker, for example, will drop the sound 6 db each time. if you were standing in the back of an auditorium, 32 feet away from a speaker not using any amplification, would you be able to hear a speaker clearly? why or why not?