I am small and made of metal. I help hold papers together. What am I?

I cover your feet and keep them warm. I always come in pairs, but sometimes I'm left all alone. What am I? Solve the riddle → I have three wheels but I'm not a car. You pedal with your feet to make me roll forward. I'm smaller than a bicycle, perfect to start with. What am I? Solve the riddle → You sit on me when you eat or rest. I usually have four legs. Solve the riddle → I live in the water and swim around. I have fins. What am I? Solve the riddle → I keep your hand warm when it's cold outside. What am I? Solve the riddle →