Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

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

What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

Which five letter word can be added at the end of below word to form a
valid word?

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> Check
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What can go through glass without breaking it?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

Keyboard words are not in alphabetical order, Why?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

What is the word or phrase?