What are the three types of comittees

What new form of music swept the nation in the 1950s a. chamber music b. hip-hop c. jazz d. rock-and-roll

2) based on the information, which is an opinion rather than a fact about immigrants to north america? immigrants

Chen's research team randomly assigned some newborns and their mothers either to a breastfeeding promotion group (where breastfeeding was encouraged, but not required) or to a normal pediatric care group (where breastfeeding was neither encouraged nor discouraged). which research method did they use?