Good Riddles

Question: What gets longer when pulled,fits between breasts, slides neatly into a hole,has choked people when used improperly,and works best when jerked?

Question: You walk into a room with a rabbit holding a carrot, a pig eating slop, and a chimp holding a banana.Which animal in the room is the smartest?

Question: What always murmurs but never talks, Always runs but never walks, Has a bed but never sleeps, Has a mouth but never speaks

Question: What did the red light say to the green light?

Question: I go up and I go down,
towards the sky and the ground.
I'm present and past tense too,
Let's go for a ride, me and you.

What am I?