Which alphabet is a part of our body?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

I’m orange, I wear a green hat and I sound like a parrot. What am I?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

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

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?

All of you like to eat me. I am a five-lettered word. Remove the first two and I turn into an infamous animal. Remove just the first and I become a heinous crime. Remove the first and the last and you can groove on me.

Can you guess who am I?

You are driving down the road in your car on a wild, stormy night, when you pass by a bus stop and you see three people waiting for the bus

An old lady looks as if she is about to die.
An old friend who once saved your life.
The perfect partner you have been dreaming about.
Knowing that there can only be one passenger in your car, whom would you choose?