Answer:
Consuming food would be pretty tough without these chompers
I know a word of letters three, add two and less there will be.
Without this, H2O would just be 2O
Humans have two that shrink in the light and expand in the dark
There is 10 birds on a branch, a man shot 5 of them. How many were left?
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?