What is the numbers of electromagnetic waves that pass by a point each second called

Match the vocabulary word with its meaning

Countries that have a traditional economy often develop at a slower pace than countries with a free market economy. true or false

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.