What Am I Riddles

Question: It's hard to give up.Remove part of it and you still have a bit.Remove another part, but bit is still there.Remove another and it remains.What is it?

Question: If you throw me out of the window,
I'll leave a grieving wife.
Bring me back, but through a door,
You'll see someone giving life.

What am I?

Question: When warm my house expands and when cold it contracts,
I am vital to a certain type of pact.

What am I?

Question: I wasn't born a horse,
and I never fly.
Yet sometimes I still soar,
right into the sky.
I often contain breath,
and yet I never die.
Sometimes I am torn,
but I never sigh.
Often, with ambition, I aspire,
and go till I can go no higher.
Then, like many men, so great,
I sink into a low state.
What am I?

Question: Four hang, four sprang, two point the way, two to ward off dogs, one dangles after, always rather dirty.

What am I?