The normal, regular rate of electrical activity for the heart is set by the:

What are the primary components of the phosphate buffer system?                       I. sodium salts of dihydrogen phosphate                    II. sodium salts of monohydrogen phosphate                   III. sodium salts of trihydrogen phosphate

A. II and III only B. I and II only C. I, II, and III D. I only

According to UNICEF, which factor is likely to negatively influence gains in height and weight in early childhood for those in developing countries?

A. Differences in socioeconomic status B. Economic differences tend to be large in developing countries; most have a relatively small middle and upper class and a large population of low-income people. C. Wealthier people have more access to nutritional foods, so their children are taller and weigh more than poorer children of the same age.