What causes seasons to change in the northern and southern hemispheres as the earth revolves around the sun?

How does central place theory explain patterns in the size and distribution of cities?

If the basis of an isosceles trapezoid have lengths of 11 and 26, what is the length of the median?

Which of the following situations is an example of an internal migration? a. moving to mexico city, mexico b. moving to san diego, califormia c. moving to toronto, canada d. moving to london, england