51.   Most of them have occurred as token clerks changed shifts or left their protective booths to empty turnstiles.

52.   Nevertheless, when an accident occurs, as with the crash of plane carrying golfer Payne Stewart and five other people on Monday, players take notice.

53.   Nonetheless, mishaps occurred as the men survived on the most remote continent on Earth.

54.   Russian officials said Friday that the latest crisis occurred as the crew was preparing for the repair mission.

55.   Serbs and Kosovar Albanians are not living together happily, and, in fact, clashes occur as a normal part of life in large towns like Mitrovica.

56.   She said the main concern is keeping health and public safety problems from occurring as residents become anxious to return to their homes.

57.   Simmons says pulmonary hypertension often occurs as a complication of another disease, such as lupus erythematosus or scleroderma and often is overlooked in the treatment of those diseases.

58.   Since these cells can turn into all other types of cells, scientists can study which genes are turned on and off as these transformations occur.

59.   Some analysts have said the narrowing gap between French and German bonds suggests increased optimism that monetary union will occur as planned.

60.   Some drifting of snow will occur as winds strengthening from the northeast.