Which issue would make ruling too hard for the government under the constitution?

When were the first 10 amendments to the constitution adopted and what was their purpose?

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?

If both the president and the vice president can no longer serve, who will become the next head of state?