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

What goes up but never comes down?

Name the three-letter word that can complete the below words:

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

There is something which is always coming but never arrives?

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

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

Living above a star, I do not burn
Eleven friends and they do not turn
I can just be visited in a sequence, not once or repeatedly
PQRS are my initials
Can you tell my name accurately?

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?