Can you find the missing piece of the Porsche?

How many times can you subtract the number 5 from 25?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?