scarcity - (3) a limited amount of resources to meet unlimited wants and needs
pollution - (2) the introduction of contaminants into the natural environment that cause negative change
national interest - (1) anything that is good or beneficial for a nation or that gives it an advantage
humanitarianism - (4) trying to protect the rights and lives of people
terrorism - (5) the deliberate use of random violence, especially against civilians, to achieve political goals
hope this helps!!