21.   If the scientists have interpreted those observations correctly, bursts may become beacons that allow astronomers to trace the history of star formation in the early cosmos.

22.   If we trace the history of a word in an unabridged dictionary, we can learn the original meaning of the word.

23.   It traces the history of the game and effect on American life, focusing especially on the Brooklyn Dodgers and the Boston Red Sox.

24.   Its galleries present exhibits that trace the history of St. Louis.

25.   Kebab history is loosely traced to the Medieval days of sword-toting warriors who frequently ate in the field during their battles.

26.   Luciano traces the history of the male pursuit of physical perfection.

27.   More important, the markers now being used to trace history have no association with appearance or with known characteristics.

28.   Participants will march in a Bastille Day parade in Les Andelys, and trace the history of Joan of Arc in the port of Rouen.

29.   Pashtuns trace their history to Qais, a companion of the Prophet Mohammed, and have sometimes claimed to be the lost tribe of Israel.

30.   Rosa added that Pentagon officials are talking to the manufacturer to try and trace the history of the device via serial number.