11.   But why do we need this extra day once every four years?

12.   Colborn said he expects to see Grieve in the majors in three or four years.

13.   Depending on the job, it will now take workers between three and four years to earn full salary.

14.   Electricity distribution tariffs are set once every four years.

15.   Even paper birch bark is smooth and reddish brown until three or four years of age turns it white and peeling.

16.   Every four years, one political candidate or another starts off strong.

17.   Few of any age can match his three tournament victories last year and now four this year.

18.   He wanted to get Altropane to market in three or four years.

19.   Her birthday comes only once every four years.

20.   His health deteriorated steadily over four years in prison.