Can you find the missing piece of the Porsche?

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

What has many keys but can’t open a single lock?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

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?

There is a five-letter word which has 3 consonants(all are same) and 2 different vowels.
Also, something wrong is associated with the word.

Can you name it?

How many sides does a circle have?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

I know there are two methods by using three time the same number with a plus(+) operator , you can make sum as 60.

One of them is 20+20+20.

whats the other way ?

Twice ten are six of us,

Six are but three of us,

Nine are but four of us;

What can we possibly be?

Would you know more of us?

Twelve are but six of us,

Five are but four, do you see?

What are we?