21.   Any one, or a combination of these, may be chosen as the basis for choosing the work-places from which a sample can be selected.

22.   In this circumstance one of these is chosen as the primary key.

23.   In any relation there may be more than one combination of attributes which can be chosen as primary key, in other words, there are candidate keys.

24.   The high ground at Richborough Castle had been chosen as Tac HQ.

25.   As suggested by Ryder and coworkers the occurrence of five or more subareas with less than six dots was chosen as the criterion for abnormality.

26.   Because of the security of such a city the Emperor Honorius chose it as a refuge capital for the western part of the Roman Empire.

27.   Position one was chosen as the first cell in the vertical column at the crypt orifice as a reference point for the computer programme.

28.   For this reason, SRY and another Y-specific gene, DYZ, were chosen as targets.

29.   The hypothesis having the minimum value of linear distance is chosen as the closest.

30.   Claire Mtayer was chosen as the new president of France Nature when the executive council of the organization met in Paris to choose a successor to Patrick Legrand.