The most common injuries in youth football occur to the

In the 1970s, what initiated an explosion of knowledge about the connections between brain and behavior?

a. new methods for observing brain activity b. looser government regulations on human experimentation c. a focus away from animal research toward human research d. the advent of the statistical method

Most people with Down syndrome have chromosomes in their cells

a. 45 b. 46 c. 47 d. 23