Ahiker is in grand canyon grand. which surface would provide the clearest echo?

the thick desert shrubs
the sandy riverbank
the rocky canyon walls
the surface of the river

In a mercantilist system a country tries to increase its blank and decrease its blank

What factors influenced brazil's current and future economic strength?

Which characteristics of temperature and salinity have the greatest influence on the movement of deep-ocean currentsa. warm and low salinityb. cold and high salinityc. cold and low salinityd. warm and high salinity