Compare the emergence of advanced civilizations in Meso and South America with the four early river valley civilizations. Which of the following might have contributed to the decline of both the Harappan and Mayan civilizations? (1 point)

a
civil war

b
failure of tropical soil

c
European invasion

d
natural disasters

The lifeguard at the local beach record the tides each day the chart below shows the high and low tides over two days

According to bowers, which of the following best describes the dominance of interest groups in the state of nevada over time? political machines dominated during the first 50 years; from 1908 to 1958 railroad and mining interests dominated; primarily gaming interests from 1958 to the present. the railroad and mining interests dominated during the first 50 years of statehood; political machines dominated from 1908 to 1958; primarily gaming interests have dominated from 1958 to present. gaming interests have always dominated. railroad and mining interests dominated from statehood until 1959; gaming interests have dominated from 1959 to present. no one interest has ever dominated at any one time.

Pj conducts an experimental study on the effects of soft music during high stakes science testing. he randomly assigns students at the school. in one condition he does not provide music for testing while in the other group he does provide the music. he administers a pretest at the beginning of the year and a posttest at the end of the year. pj’s design is best described as a: a. static group comparisonb. pretest-posttest control group designc. control-group-time-series designd. nonrandomized control-group pretest-posttest design