An Earthquake is a sudden tremor or movement of the earth's crust, which originates naturally at or below the surface.The word natural is important here, since it excludes shock waves caused by French nuclear tests, man made explosions and landslides caused by building work. There are two main causes of earthquakes.n Earthquake is a sudden tremor or movement of the earth's crust, which originates naturally at or below the surface.
Definition of TANGRAM. : a Chinese puzzle made by cutting a square of thin material into five triangles, a square, and a rhomboid which are capable of being recombined in many different figures.See tangram defined for kids. ADVERTISEMENT.efinition of TANGRAM. : a Chinese puzzle made by cutting a square of thin material into five triangles, a square, and a rhomboid which are capable of being recombined in many different figures. See tangram defined for kids. ADVERTISEMENT.
The actual origin of tangrams is unknown. However, it is known that tangrams was a popular recreation in China near the start of the nineteenth century. This was followed by a craze in America, Europe, and Asia where it was one of the most popular games of the nineteenth century.