Which of the Following Occurred During the 20th Century

question 44

Multiple Choice

Which of the following occurred during the 20th century?

• A) The total U.S. population increased.
• B) The percentage of foreign-born residents decreased, on average.
• C) The median age fell.
• D) All of the above occurred during the 20th century.

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Definitions:

Globulin

One of a class of proteins in blood plasma, some of which (gamma globulins) function as antibodies

Erythropoietin

A peptide hormone secreted mainly by kidney cells; stimulates red blood cell production.

Circulatory System

The body system that transports nutrients, oxygen, carbon dioxide, hormones, and blood cells to and from cells in the body to nourish it and help fight diseases.

Vertebrate

An animal possessing a backbone or spinal column, including mammals, birds, reptiles, amphibians, and fish.