You can see it everyday, But cannot touch it at will. What is it?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

What goes up but never comes down?

A bus driver was heading down a street in Mexico. He went right past a stop sign without stopping, he turned left where there was a "no left turn" sign, and he went the wrong way on a one-way street. Then he went on the left side of the road past a cop car. Still - he didn't break any traffic laws. Why not?

I have teeth but i don't bite. Who Am I ?

What can you catch but never throw?

What word is pronounced the same if you take away four of its five letters?

If a boy blows 18 bubbles,
Then pops 6 eats 7 and then
He pops 5 and blows 1.
How many are left?

What runs around the whole yard without moving?

I look at you, you look at me, I raise my right, you raise your left. What am I?