Study the major rivers on the map of the United States. Which river is marked with the letter B?
O Colorado River
O Columbia River
O Missouri River
O Ohio River

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.