What does this rebus puzzle means ?

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?

No matter how little or how much you use me, you change me every month. What am I?

What is the fastest way to double your money?

The teacher told the student that if he told a lie then he will be expelled from school and if he told the truth then he still is expelled from school.

What can a student say to prevent his being expelled from school?

A man was just doing his job when his suit was torn. Why did he die three minutes later?

What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

Rectify the following equality 101 - 102 = 1 by moving just one digit.

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?