11.   The latest ice breakup occurred in the Larsen B ice shelf, which has probably existed since the last ice age.

12.   There are still some signs of the social alliances that have existed since the Great Depression.

13.   These problems have existed since way before cell phones, but the LIRR has largely ignored them.

14.   This phenomenon has existed since the beginning of TV.

15.   This built-in bias against secondary earners has existed since shortly after World War II, McCaffery said.

16.   This problem has existed since the founding of the Turkish Republic, and it has to be confronted.

17.   When Carnahan was lieutenant governor, Ashcroft was governor, and an undercurrent of ill will has existed since between the two.

18.   Zirconium was chosen, the document said, because a production process for it already existed since the metal was used for incendiary bombs.

19.   According to the Academy of General Dentistry in the United States, flossing has been proven by anthropologists to have existed since prehistoric days.

20.   Both victims and rioters of the Rengasdengklok asserted that disparity has existed since the colonial period.