Answer:
As evolutionary biologists have shown, this multicellularity was linked to the rise in oxygen and thus played a significant role for life on Earth as it is today. ... By producing oxygen and evolving into multicellular forms, they played a key role in the emergence of organisms that breathe oxygen.
Explanation:
Answer:
Explanation:
Use the following equation:
and solve for F:
and filling in:

F = 4.0 ×
N
Apply:
wavelength = speed/frequency
= 350 m/s : 140 Hz = 2.5 m.
45 because you see it in a hot min.