How many triangles do you see in the picture puzzle below?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

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?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

There is something which is always coming but never arrives?

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?

What is always in front of you but can’t be seen?

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?