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

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?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

Which five letter word can be added at the end of below word to form a
valid word?

> Pin
> Check
> Boiling
> View

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

There are two words one resembles the "state of rest" and the other is related to "writing/reading material".

Can you name these two words which also sound similar?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

A horse was tied to a rope 5 meters long and the horses food was 15 meters away from the horse. How did the horse reach the food?

Why is it against the law for a man living in Delhi to be buried in Mumbai?

Which of the following words don't belong in the group and why?
CORSET, COSTER, SECTOR, ESCORT, COURTS