Can you name an animal whose killing cannot be performed without spilling your own blood?

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

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Make a sentence consisting of three words that have the whole alphabet.

I am sure no one can have two things for dinner. what are they?

What is both possible and impossible at the same time?

A boy was locked in a room by some robbers. All that is in the room is a piano, a calendar, and a bed. The room is locked from the outside. What does he eat, drink, and how does he escape and get out?

I can be made.
I can be cracked.
I can be told.
I can be played.

Who am I?

I have branches, but no fruit, trunk or leaves. What am I?

Which city is three-fifths chick two third cat and 50% goat?