Concerning category hierarchies, children first use:

When he was 6 years old, Perry used to chase his older brother, Marcus, in the backyard, but got winded sooner than Marcus did

Now that Perry is a 9-year-old, he can run faster and longer than ever before and has less trouble keeping up with Marcus's pace. This is a result of increased ____ in middle childhood. a. lung capacity b. fine motor movement c. flexibility d. myopic vision

Which of the following have been used in treatment for smoking cessation?

a) antidepressants b) anxiolytics c) stimulants d) acetaminophen