What says that a whole is equal to the some of its parts

This word for a bug or malfunction was popularized in the 1962 book into orbit by the mercury astronauts

Match the graph type to its description. 1. uses symbols to describe information pie 2. compares different quantities at the same point in time line 3. compares increases and decreases in a quantity over a period of time bar 4. shows the relationship of parts to each other and to the whole pictograph

Why is immigration so important today?