Which activity involves only a physical change?

a. acid bubbling on a rock
b. grinding coffee beans
c. exploding fireworks
d. baking cookies

Explain how ancient whale fossils found in eqypt are believed to support the theory of evolution.

The united states produces an average of 429 billion pounds of food annually. about 133 billion pounds of that food ends up as waste.the percentage of food that the united states wastes each year is %.

Which of the following is not a food produced in rainforests? a) coffee b) cocoa c) avocados d) wheat