I’m the background paragraph what does the word underground mean plzzz got only 5 min

What best explains why the us government placed restrictions on asian immigration through angel island? many americans did not believe in assimilation. many americans did not approve of the gentleman’s agreement. many americans held nativist or racist views. many americans feared a loss of educational opportunities.

Which was not a reason for the fall of the han dynasty? neglected farmland civil war decline in trade peasant rebellions foreign invasions

Which would be good historical evidence when studying manifest destiny?