2. Why is it difficult for us to go up in a mountain than go down? A We are moving against gravity
B. We are pulled by the wind
C. We are moving towards gravity.
D. None of the above
Farth

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Transportation is the largest single source of air pollution in the united states. air pollution can harm the environment and human health. which technology could offer a solution to this problem? mufflers that reduce noise motors that run on electricity tires that improve gas mileage

Astring vibrates with a frequency of 10 hz. why can't a person hear the sound waves produced by the vibrating string, no matter how large the amplitude of the waves? out! this is homework and due tomorrow! you so much!

How might this scientific phenomena be explained? a paper clip floats on water.