Cold dense air near the poles sinks. It moves toward the equator and is heated then rises. The warm air then moves back to the poles where it is cooled and sinks again.

What causes these differences in air temperature on earth?

Please help. I will appreciate it.

97 points what types of changes have been made in the united states to protect people from earthquakes? a. communities are no longer located along fault lines. b. building codes ensure that structures can withstand shaking. c. warnings go off when an earthquake is expected, and people evacuate the area. d. barriers have been built to prevent flooding by a tsunami.

For each of the following examples of data, determine which scale of measurement is used. a) the number of miles joggers run per week. b) the starting salaries of graduates of mba programs c) the months in which a firm's employees choose to take their vacations. d) the final letter grades received by students in a math course.

Which entity owns most if the television stations, radio stations, and newspapers in the united states