What was most remarkable mayan achievement based on there architecture

Apex! which term describes the expanse of flat land in this photograph? (see picture) a.) mountainb.) plainc.) rift valleyd.) plateau

According to the population pyramid, in 2000 china had about 120 million people in which age-group

Which of the following is an important principle of how water moves through a watershed? a. most freshwater is in the form of ice. b. small streams flow into larger streams. c. each watershed contains only a single source of water. d. clouds are formed through evaporation and then condensation.