This probably occurs because of the sparse food supply that can be found.

Sometimes they occur because of maintenance problems at treatment plants.

American officials said the shift occurred because of security concerns about possible demonstrations during the visit.

This occurs because of the pressure needed to expand the lungs for the first time.

However, change may occur with the seasons because of fluctuations in the ground water.

But it is unclear if any occurred because of a decrease in available care.

Whether a mutiny would have occurred just because of this, we can't know.

This mixing occurs because of the difference in their concentrations.

Secondary means it occurs because of another disease or situation.

Similar effects may also occur because of common medical problems or other indoor air pollutants.