What kind of law is Congress given permission to pass under the U. S. Constitution?

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?

How can christianity affect the cultural landscape of a place?

Can someone me answer all the questions?