They can last up to a week depending on the model's body chemistry.

You've reminded us that we share the same body chemistry with Outsiders.

We can't leave this world without some pretty basic changes in our body chemistry, which we've always been denied.

It should be pretty well tuned now to his body chemistry.

Before we tried that, we'd have to know his body chemistry.

Muscles were one thing, but internal body chemistry was quite another.

At once their furious body chemistry gave aid to its own.

The method of travel is mysterious, but it results in changes to body chemistry.

And which changes your body chemistry such that the only way to get any nutrients is to continue taking the pills.

They tell each other the news with their body chemistry.