Obstacles can be practical.Logical formLearned from310 sentences. Obstacles can be difficult.Logical formLearned from305 sentences. Obstacles may pertain-to a person.Logical formLearned from283 sentences. Obstacles may pertain-to a male.Logical formLearned from253 sentences. An obstacle can be to a (peace process).Logical formLearned from226 sentences. An obstacle can be to progress.Logical formLearned from220 sentences. An obstacle can be to development.Logical formLearned from207 sentences. An obstacle can be difficult.Logical formLearned from202 sentences. Obstacles may be overcome.Logical formLearned from190 sentences. Obstacles can be to trade.Logical formLearned from188 sentences. Variety can be constituted-of-or-filled-with obstacles.Logical formLearned from180 sentences. Obstacles may be overcome.Logical formLearned from175 sentences. An obstacle may pertain-to persons.Logical formLearned from170 sentences. Obstacles can be institutional.Logical formLearned from164 sentences. An obstacle can be fundamental.Logical formLearned from162 sentences.