Which class doubled in size during the years between 1900 and 1925? A. wealthy class
B. working class
C. middle class
D. farming class

Computer models can scientists predict weather. some computer models can show the predicted path of hurricanes. what other events could a computer model warn us of? a) undersea earthquakes , tornadoes, and avalanches b) tornadoes c) avalanches d) undersea earthquakes

Which of the following factors is not used to measure a country’s standard of living? a.) life expectancy b.)educational levels c.)divorce rates d.) gross income

5. what is a red giant? can our sun become a red giant? why or why not?