What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

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

A man in a car saw a Golden Door, Silver Door and a Bronze Door. What door did he open first?

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

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

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

What has 88 keys?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth, I am dissolved into air. What am I?