bogan
Milk.
More humans.
Humans can indeed be considered carbon sinks. Not only do humans have a lot of carbon in them they also use a lot of carbon.
An ionic bond.
If you consider a substance JWH-108 that is human made and not completely studied on effects on humans bad then yes.
it is a substance
bogan
For humans, the waste substance is carbon dioxide.
It is the degree of which a substance can affect humans. A toxin or a poison.
humans and acid
no
Lunch.
Milk.
no they have to bite you
Most humans are considered omnivores, but again there are vegetarians and vegans
Insulin, is an organic substance and is needed in humans for the absorbtion of sugars.