How did theodore roosevelt conserve the nation's land and resources

This researchers data could him determine which of the following types of information about great britain during the industrial revolution

What was the purpose of the u.s navy's convoy system

Which of these did the soviet union do in 1961? it built a wall through berlin to keep people from moving to the west. it used force to destroy a wall the united states had built in berlin. it convinced the british and french to merge their zones in berlin with the soviet zone. it threatened to bomb berlin if the united states did not leave within 30 days.