Keli leamed that an air mass is a very large body of air with similar temperatures, humidity, and pressure, and that air masses are constantly in motion. She knows the air masses change, depending on the temperature and moisture content of the region where they form. She looked up
more information about what makes them move. What are the major causes for moving air masses in North America? Choose the two that apply
O A. changing humidity
B. low temperatures
C. jet stream
D. prevailing westerlies