I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Can you guess the name of the month by looking the below rebus ?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

Decode this picture on T-Shirt and tell what it says ?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

Given below is simple addition with a defined pattern pattern:
7 + 7 = 2
8 + 8 = 4
8 + 5 = 1
6 + 9 = 3
10 + 11 = 9

Can you analyze the pattern and find out the answer for:

4 + 9 = ?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?