'Gram', 'kilogram', and 'metric ton' are units of mass, not weight.
'Pound' can be either a unit of mass or of force. Most people
use it most of the time to mean weight.
Humans affect the eath by burning fossil fuels
Answer:
Scientists believe that light is made of waves because experiments have shown that, based on Huygens's principle, waves have the ability to bend and change direction.
Explanation:
Assuming classical mechanics, D.
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