The neurotransmitter _____ is suspected to play a role in attention-deficit disorder

Compared to other Western nations, U.S. teenage pregnancy rates are:

A) higher. B) lower. C) similar. D) lower or higher, depending on the country to which the United States is compared.

Devonte, a 13-month-old, grabs his mother's keys that were laying on a nearby table. How is Devonte likely to explore this new object?

A. By turning it over in his hands B. By putting it in his mouth C. By smelling it D. By putting it up to his ears to listen