How you made money

A young man asked ................old rich man how he made his money.
1. a
2. an
3. the
Well, son, it was 1932. The ................of the Great Depression. I was down to my last nickel.
1. depth
2. deep
3. deeping
I invested that nickel in an apple. I spent the entire day polishing .................. apple and, at the end of the day, I sold the apple for ten cents.
1. a
2. the
3. /
The next morning, I invested those ten cents in two apples. I spent the entire day ............. them and sold them at 5:00 pm for 20 cents.
1. polish
2. polishing
3. polished
I continued this system for a month, .......... the end of which I'd accumulated a fortune of .37.
1. for
2. in
3. by
And that's how you ............ an empire?" the boy asked.
1. built
2. builded
3. building
Heavens, no! the man replied. Then my wife's father died and left us two million dollars.
1. Then
2. Than
3. As