What do topographical maps use to show altitude changes? contour lines changes in color keys and symbols grid lines

i think its contour lines

1 and 3

explanation:

learned it in 6th

after world war ii, the united states and the soviet union were the major economic, military, and political powers. the world was bilateral multipolar bipolar unilateral

after world war ii, the united states and the soviet union were the major economic, military, and political powers. the world was bipolar.  

the great leap forward, mao zedong's plan to increase china's agricultural and industrial production, was an overwhelming success. true false

the great leap forward, mao zedong's plan to increase china's agricultural and industrial production, was an overwhelming success. true.

explanation: