What event led the united states to declare war on germany during world war 1?

What is significant about official languages in russian republics? why would it matter?

The dravidians descended from people who lived in

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