Attention-deficit/hyperactivity disorder has been linked to irregularities in the way which of the following neurotransmitters operates in the brain?

Approximately what percentage of volunteer coaches lack the necessary formal preparation to coach?

A. 30% B. 60% C. 65% D. 90% E. 95%

One particular confound for the use of an adoption study of heritability is the phenomenon of _____ placement, in which a child is placed in a home that is similar to the home of the biological parents

A) unilateral B) forced C) matched D) selective