Please help me I need to pass my class

Surface currents are caused by blank space . question 14 options: surface currents are caused by? differences in water temperature high salinity differences in density wind forces

If two objects at different te,peraure are in contact with each other what happens to their temperature

6. using 3 – 4 sentences explain (in your own words) why water expands when it freezes? 7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation.