Best difficult riddles

You draw a line. Without touching it, how do you make the line longer?

Whats the difference between love and marriage?

What do you get when you cross a fish with an elephant?

What do you call an elephant with wings?

What do you get if you cross cat with an elephant?

What do you call an angry polar bear?

This guy living on the 20th floor in an apartment building got up early each morning to go to work in a downtown store. He always went into the elevator on the 20th floor and rode down to the entrance (1st floor). When he came home he always rode the elevator from the entrance and up to the 8th floor. He walked out of the elevator and walked the stairs up to his apartment on the 20th floor. Why didn't he take the elevator all the way up to his apartment?

I’m teary-eyed but never cry, silver-tongued, but never lie. double-winged, but never fly, air-cooled, but never dry. What am I?

Large as a mountain, small as a pea, Endlessly swimming in a waterless sea.

If there are four sheep, two dogs and one herds-men, how many feet are there?