Reparation of consumers. For example when humans exhale they send carbon dioxide back into the atmosphere.
<span>D) reduce the amount of electricity he uses.( good luck m8 tell me if I'm wrong</span>
I would say B because A doesn’t have a ring to it.
Waves are produced by Earthquakes
Lots of hand waving as is in the current field of much of molecular biology. Other than that experiments and observations. Basically the utilization of the scientific method and then trying to find the mechanism by which something occurs through even more research/experimentation.
HOPE THIS HELPS