21.   There was a series of detonations around the base of the condemned building, causing it to come crashing down in a matter of minutes.

22.   There have been a series of holdups at local banks.

23.   Dilution viscometers are most convenient when a concentration series is to be measured.

24.   Where there are a series of slits, each slit acts as a source of spherical or circular waves.

25.   In between these two bounds there can be a series of different approaches to meet each case on its merits.

26.   The Doctor explained that in the late nineteenth century there had been a series of unsolved murders committed in the East End of London.

27.   This series would have been a non-starter without the help of Judith Glynn from the London School of Hygiene and Tropical Medicine.

28.   Of the three haematopoietic cell lines, the granulocyte and megakaryocyte series were normal and the erythrocyte line was hyperplastic.

29.   If so, this series is unlikely to have been conspicuous after the third quarter of the second century.

30.   There is a series of complex rules for determining the true length of a lease.