What is this mask name?

What is one result of the supreme courts decision in the mccullough v maryland case

One drawback of voluntary trade is that it a.requires two groups to use a common language b.can make one group dependent upon another for necessary goods c.doesn't occur unless there is a shortage of goods for at least one group d.forces groups to rely on themselves to produce all the goods they need

Which answer choice best describes “panning” for gold? a.) miners ran iron pans along the rocks near streams. because gold is magnetic, any gold that was present in the rock would attract the pans. the miners would then pick away the surface of the rock to expose the gold. b.) miners ran water through a long, sloping wooden box called a “pan.” wooden bars across the bottom of the pan trapped any gold that was in the water. c.) miners went to places where stream currents slowed. they gathered rock from the stream bed into flat pans. any heavier gold particles would drop to the bottom of the pan. d.) after the most obvious gold had been taken, miners used a rock-crushing machine called the “pan” to search for gold on a large scale.