What happened when the wheel was invented?

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

Can you place six X (crosses) in below board without making three in a row in any way ?

I am green and found in the forest and have needles instead of leaves. What am I?
Hint 1: It can be used for Christmas decorations.
Hint 2: I have a strong, scent that is used in air fresheners.

John was piloting a plane behind a car but was never able to overtake it. Why?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

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

Find the number of squares in the below-given picture.