Good Riddles

Question: Railroad crossing without any cars. Can you spell that without any R's?

Question: What has 6 wheels and flies?

Question: A monkey, a squirrel, and a bird are racing to the top of a coconut tree. Who will get the banana first, the monkey, the squirrel, or the bird?

Question: what is in the middle of the sky?

Question: What can float but can't sink.