Where is 'Beavis and Butt-Head' set?

Where is 'Living Single' set? Who created 'Living Single'? On which network did 'Beavis and Butt-Head' originally air? In what year did 'Beavis and Butt-Head' premiere? Who created 'Beavis and Butt-Head'? In what year did 'Friends' premiere? Who created 'Friends'? On which network did 'ER' originally air?