In the 1960s, mao sent the red guards across china to a. destroy the chinese economy b. force people to join communes c. protect old ways of thinking about communism d. destroy old ways of thinking about communism (gradpoint)

Tides are caused by a differences in the gravitational force of the sun at different points on earth. differences in the gravitational force of the moon at different points on earth differences in earth’s gravitational field strength at different points on earth’s surfac fluctuations in the gravitational attraction between earth and the moon.