What word begins and ends with an E, but has only one letter?

Give it food and it will live; give it water and it will die.

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

I know a nine-letter word having only one vowel.
Do you ?

The dirtier I get, the whiter I look. Who am I?

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.