Most nerve cell fibers outside the brain and spinal cord are wrapped by a thin layer of cells that form a "tunnel" that damaged fibers can follow as they repair themselves. This thin layer of cells is known as __________

The information-processing theory of development likens human cognitive processes to the functions of a

a. motorcycle b. cellular phone. c. computer. d. television

An event's relative frequency in the population equals

a. 100%. b. the average number of times an event occurs in the population. c. the odds of the event. d. the probability of the event.