Name the three-letter word that can complete the below words:

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E

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

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.

A blonde put eyeliner on her head. Why?

I am the fastest animal but cannot climb the tree. What am I?

Bopanna was working on a murder case when he received a message about the location of the murder weapon.
The message was encrypted as below.

"deb mitciv eht edisni neddih si nopaew redrum ehT"

Tell me the location of the murder weapon.

Make a sentence consisting of three words that have the whole alphabet.

Name a key which is hardest to turn.

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

Can you count the number of triangles inside a triangle?