Answer:
What was the first man made invention that could see through a wall?
What is yours but only used by others?
It is a gruesome form of betray.
I can be found in seconds, minutes and centuries, but not in days, years or decades.
A standard dimension for sandwiches and rulers
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?