Good Riddles

Question: What runs around the house but doesn't move?

Question: What happens when you throw a blue rock into the yellow sea?

Question: What grows up and down at the same time?

Question: Scientists are trying to figure out what is between Heaven and Earth.What is it?

Question: Tom wants to send Sally an expensive ring through the mail because they live thousands of miles apart. The only problem is that everything sent through the mail is stolen unless there is a lock put on it. Both Tom and Sally have plenty of locks and keys but they don't have any of the same locks or keys.

How can Tom send Sally the ring without it getting stolen?