Research on stress indicates that stress causes cancer

To say that a young infant's interaction with the environment is reflexive means that the infant

A) can engage in trial-and-error learning in a logical and intentional manner. B) can intentionally respond to the environment through physical and mental actions. C) can engage in trial-and-error learning without anticipating a specific outcome. D) reacts to the environment without having voluntary control over his or her actions.

By age 5, human children have a vocabulary of between ________ words

a. 100 and 500 b. 500 and 900 c. 1,000 and 5,000 d. 5,000 and 10,000