Kids Riddles

Question: Weight in my stomach,trees on my back,nails in my ribs,it's feet I lack.What am I?

Question: I am a digit, but two of the ten.
Two of me make a promise.

What am I?

Question: If you toss a coin ten times and it lands heads up every time, what are the chances it will land heads up if you toss it again?

Question: What has to be broken before you can use it?

Question: 16 06 68 88 ? 98.

What is the '?'?