The concentration of thyroid hormone in the blood must itself vary.

The concentration of these smaller groups often varies greatly across the country.

You can expect that his concentration will vary, however, and your visits should be short.

Its atmospheric concentration varies greatly depending on the season and conditions.

Its concentration for use in endodontics today varies from 0.5% to 5.25%.

The concentration of the acid as the active ingredient can vary.

The concentrations of tea tree oil used in studies have varied depending on the medical condition.

The concentrations of different volcanic gases can vary considerably from one volcano to the next.

While concentration varies among grape varieties, it is usually found in higher levels with red wine grapes.

Natural C production and hence atmospheric concentration varies only slightly over time.