What are three things Daniel Sadoway says he and his team have learned from this
project?

Its either a) or b),wind and water erosion gradually widen the canyon

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on

Since we don't see a strand; i got answers off a sheet and the correct answer is "2".

B, because u need evidence to support ur theory and claim and it needs to be correct evidence