Which nation tested a nuclear weapon underground in 2009

During the 19th century the united states government reacted to the union attempts to organize labor by

Awriter agreement is what ? a. contact b. investment c. solvency d. tariff

Which effect did the united states supreme court's decision in plessy v. ferguson have? 1. ending segregation in all public schools in america 2. protecting voting rights for african americans by eliminating literacy tests 3. upholding the rights of all citizens to be treated equally by the government 4. authorizing the system that kept black and white people separated