21.   Stoichiometry is the study of the quantitative composition of chemical substances and also the quantitative changes that take place during chemical reactions.

22.   Thus Reactants Products The composition of chemical compounds and the changes in composition that take place during chemical reactions are governed by four important laws.

23.   The Quinton multiple biopsy instrument was introduced to a position corresponding to the ligament of Trietz and left in place during the study.

24.   Notice was given of two outside courses taking place during February.

25.   The exchange took place during Scottish Question time.

26.   The lessons took place during the evening and then only after I had finished my regular school work for the day.

27.   In a number of countries a distinct shift took place during the course of the boom.

28.   Also, one of the fiercer collisions perhaps of any training camp this summer took place during a recent San Diego practice.

29.   And his happiness started to fall into place during the worst season of his life.

30.   And I believe we must examine the events which took place during the last election and attempt to give the American people some answers to some very unsettling questions. . . .