Why did admiral Yamamoto decide to attack midway?

Ineed to write an essay about harriet tubman

Me i really need which of these was an accomplishment of the han dynasty? the invention of the seismograph finding a water passage to europe the invention of the ballpoint pen the invention of the abacus

What did this mean for dred scott? a.scott was not a citizen of the united states. b.scott was the property of the federal government. c.scott had no right to sue for his freedom in court. d.scott was considered the property of the slaveholding family.