A period may vary in time, but is usually 30-90 minutes long.

The other two members of the team vary in the series.

However, these countries vary in terms of their economic development.

The students are varied in their economic standing, as well.

The class now varies in size from three to five members.

These vary in price and quality, but several are very good indeed.

The number of employees varied between 200 and 300 in those years.

The group she ran last fall varied in size from 6 to 12 women.

The particular form that the training takes varies in different countries.

Schools varied in their concern for a number of other issues.