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?
Exposure to sunlight helps a person improve his health because
Options: the infrared light kills bacteria in the body, resistance power increases, the pigment cells in the skin get stimulated and produce a healthy tan, the ultraviolet rays convert skin oil into Vitamin D