Obstacles can be perceived.Logical formLearned from77 sentences. Obstacles can be to success.Logical formLearned from76 sentences. An obstacle can be to progress.Logical formLearned from76 sentences. Obstacles can be environmental.Logical formLearned from75 sentences. Obstacles can be daunting.Logical formLearned from75 sentences. Persons may face obstacles.Logical formLearned from75 sentences. An obstacle can be to recovery.Logical formLearned from74 sentences. Obstacles can be challenging.Logical formLearned from74 sentences. Obstacles can be insurmountable.Logical formLearned from74 sentences. Some obstacles may be overcome.Logical formLearned from74 sentences. An obstacle can be in a path.Logical formLearned from73 sentences. An obstacle can be to success.Logical formLearned from73 sentences. An obstacle can be to economic growth.Logical formLearned from73 sentences. Obstacles can be man-made.Logical formLearned from73 sentences. An obstacle can be on a road.Logical formLearned from72 sentences.