Why have locks been created between the great lakes and the st. lawrence river

Iam stuck on this question! 45 points : ) how do increases in temperature affect the density of ocean water? answer choices: (a) density does not change (b) density increases (c) density becomes variable (d) density decreases

Wegeners theory of continental drift states that the continents have changed throughout history while the theory of plate tectonics

Countries that have a traditional economy often develop at a slower pace than countries with a free market economy. true or false