Why is 6 afraid of 7?

what does the below math rebus puzzle mean?

There is a place where if I stand up straight, I will still be considered sideways.

How can you tell a raw egg from a hard-boiled egg?

How can you make a TV, a bed, a dog, and a car liquid?

What question can you never answer yes to?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

The more you take me, the more you leave me behind.
Who Am I?

Katniss and Peeta are liars. They both lie on some specific days.

Katniss lies on Fridays, Saturdays and Sundays. She speaks the truth on all other days.

Peeta lies on Tuesdays, Wednesdays and Thursdays. He speaks the truth on all other days.

Can you tell that one day of the week when both of them will say "Tomorrow, I will lie."?

ENEMY = 2 * LINK
LINK + 2 = HELL

Then what will be TAXI + HELL? Select from the options below:
a) ROTTEN
b) DANGER
c) HEAVEN
4) MORTAL