public void clearAllTables()
{
Groups.RemoveRange(Groups);
AnswersByPhone.RemoveRange(AnswersByPhone);
//Rooms.RemoveRange(Rooms);
//Teachers.RemoveRange(Teachers);
MeasureInstructionsData.RemoveRange(MeasureInstructionsData);
OneMeasuresEvalData.RemoveRange(OneMeasuresEvalData);
OneMeasuresByGroupId.RemoveRange(OneMeasuresByGroupId);
MeasurementsByGroupId.RemoveRange(MeasurementsByGroupId);
Measurements.RemoveRange(Measurements);
ActiveExperiments.RemoveRange(ActiveExperiments);
Experiments.RemoveRange(Experiments);
Activities.RemoveRange(Activities);
ActivityLogs.RemoveRange(ActivityLogs);
//Students.RemoveRange(Students);
SaveChanges();
}
