People are biological creatures as well as rational human beings. In order to gain a complete understanding of any aspect of human behavior, the field of anthropology adopts what strategy?
1. ethnobiology
2. a four-field approach
3. cultural evolution
4. physical anthropology

One important development during the 3rd trimester that will insulate the infant against changes in temperature is a. the deposition of fat under the skin b. the closing of the septum between c. the atria of the heart d. the beginnings of lung functioning e. the beginnings of light and sound sensing