I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

An inspection by the superintendent of St. Joseph School was scheduled on the next day. The class teacher Jenifer knew that he would be asking questions from her class and she would have to choose a pupil to answer. To offer a perfect impression over him, the teacher explained certain instructions to the students to maximise the chances of getting correct answer every time.

What did she say to the students?

The following alphametic has only one solution. Can you find it?
ENLIST + SILENT + LISTEN = ANAGRAM

PS: You may start the number from 0.

Why do people go to bed?

Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

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

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?