Options: absorption of corresponding wavelengths by the outer layers of the sun, destructive interference between waves of certain definite wavelengths, absorption of corresponding wavelengths by the prism used in the photograph, absence of corresponding wavelengths from the light emitted by the core of the sun
Benjamin Franklin was a prolific inventor. He invented the lightning rod, the Franklin stove, studied electricity, discovered the Gulf Stream, started the first library, and on and on. Among his many other inventions, what musical instrument did he invent?
It is more difficult to walk on a sandy road than on a concrete road because
Options: sand is soft and concreter is hard, the friction between sand and feet is less than that between concrete and feet, the friction between sand and feet is more than that between concrete and feet, the sand is grainy but concrete is smooth
Options: whenever the normal decrease of atmospheric temperature, when the decrease in temperature or moisture or both takes place, whenever the normal decrease of atmospheric temperature or moisture or both change with height over a short vertical interval, All of the above