What challenges is Brazil currently addressing?

What specific science discipline do most social engineering attacks rely on when they are being used?

Which action best represents the policy of appeasement followed by britain and france prior to the start of world war ii? (a)allowing hitler to annex the sudetenland as part of the munich agreement (b)signing the nazi-soviet pact binding hitler and stalin to peaceful relations (c)sending troops to fight with the liberals during the spanish civil war (d)forbidding the sale of arms to any nation at war

What challenges did nigeria faced after it gained its independence from britain