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

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

There’s a one-story house in which everything is yellow. Yellow walls, yellow doors, yellow furniture. What colour are the stairs?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

What do you call a fish without an eye?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

Today, I celebrated my 32nd birthday but I was born in 1972.
How is this possible?

I look at you, you look at me, I raise my right, you raise your left. What am I?

A spy was in Canada trying to steal insider information on how to set up new Maple Syrup factories in their country. He was introduced to the operations manager of the biggest factory in Canada. However, the manager was suspicious and decided to test him with a question before he trusted him. So he asked, “What would you be sure to find in the middle of Toronto?” The spy thought fast and came up with an answer for the manager. What was his answer?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?