Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

It belongs to you, but other people use it more than you do. What is it?

On the dull night when the blonde was dozing, she heard an odd clamour and she saw that there was a bizarre man with a gun simply outside her home. So she raced to the telephone to call the police, however, she can't dial 911. Why?

You can hear me, but you can't touch or see me.

What am I?

What's the only room from which no one can enter or leave

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Forwards I am heavy, backward I am not. What am I?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

In a supermarket, there is an intelligent glass pane before a refrigerating unit. This glass pane allows cherries and apples through it but does not allow grapes and Orange to pass through it.

Can you identify the rule that the glass pane is following?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100