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

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

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

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

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?

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

Which English verb becomes past tense just by rearranging the letters?

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

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

It is always ahead of me yet I can never see it. What is it?