Oil accounts for over 90% of angola's exports, but the country must import over half of its food. other countries in africa, however, do not produce oil but are able to export food products. based on this information, which statement is true?

Which research model refers to the study of an individual, group, or community over a predetermined period? a. cross-sectional model b. sectional model c. cross-sequential model d. longitudinal model

Canada economy usa test prep i am stupid i don’t get it

According to the federal regulations, which of the following studies meets the definition of research with human subjects? a. a researcher uses the customs office’s passenger lists for ships bringing immigrants to the us between 1820-1845 to track the numbers of immigrants from certain ethnic groups.b. a researcher conducts a linguistic study of comments posted on a local public blog.c. a developmental psychologist videotapes interactions between groups of toddlers and their care givers to determine which intervention methods most effectively manage aggression.d. a researcher asks the director of a local free clinic about the number of patients in the last two years with newly diagnosed hiv/aids.