11.  Some iron is lost in sweat, and, for unknown reasons, intense endurance exercise is sometimes associated with bleeding of the digestive system.

12.  For some unknown reason it has moved eleven times.

13.  She averaged practically all of my marks for some unknown reason.

14.  An agreement was announced but fighting began later, for unknown reasons.

15.  Bales has also considered the possibility that someone in the federal government wanted to shut up Bell for some unknown reason.

16.  A young female volunteer suffering from convulsions for unknown reasons also was taken to a hospital, he said.

17.  About two hours after I first installed the CyberMouse, it stopped working for unknown reasons.

18.  All of the unclaimed freight was disposed of, but for some unknown reason, his grandfather held onto the package.

19.  Brewer said his office has attempted to have Fred Goldman named as a plaintiff in the lawsuit but he was uninterested for unknown reasons.

20.  But a captive breeding program under way at the Hope Zoo and six American zoos has failed to produce any offspring, for still unknown reasons.