When a hair dryeris being used, one of the energy transformations that takes place is

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?

Why is it necessary to obey social norms? write briefly.

Why do you think americans were so fascinated by this idea of the united states stretching from “sea to sea”? give 2 reasons