What work can one never finish?

Can you divide the below-given shape into four equal and identical pieces?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

I have Rs.50 and I spend it in the way as below.

What is at the end of a rainbow?

In The 1st month of this year(the year 2013), I noticed that the date 13-1-13 (13 January 2013) is special.

This date is special as:

Date * Month = Year.

Can you figure out which year of this century has a maximum number of such dates?

Its something that each of us devours,
Not just us but birds, beats, trees, and flowers,
Frets iron and nibbles steel,
Toil hard stones to meal,
Exterminates king, collapse town,
And blows the mountains down.

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

What is the end of everything?

I know a nine-letter word having only one vowel.
Do you ?