Cervical cancer is caused by severe abnormal changes in the cells of the cervix. Most precancerous or cancerous cell changes occur in the cervix at the transformation zone, because these cells normally undergo constant change.
In baseball, a balk is called by an umpire. Balk rules protect runners from being deceived by the pitcher. If the ball is thrown before the batter gets settled in the batter's box, the umpire will call a balk. If a pitcher begins his delivery motion but then stops, he'll be called for a balk.
Obstruction (baseball) For interference including by a catcher, see Interference (baseball). In baseball, obstruction is when a fielder illegally hinders a baserunner running within the basepath. Baserunners are generally permitted to run from base to base without being physically blocked or hindered by a fielder.