What did Eratosthenes calculate using distances between two cities and
the length of a shadow?

Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? a. the chlorofluorocarbons act like ultraviolet radiation causing large amount of ozone to be produced. b. the chlorine from the chlorofluorocarbons reacts with free molecules of oxygen causing a stop in ozone production c. free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone. d. chlorofluorocarbons absorb ultraviolet radiation, preventing the formation of ozone select the best answer from the choices provided

Prompt compare the three types of volcanic mountains in terms of shape, type of eruption, and the minerals that make up the volcano

Vessels draining the myocardium of the heart, open primarily ,into which chamber?