(Riot police) may prevent students from marching an allusion to freedom of assembly.Logical formLearned from6 sentences. Police may prevent an (opposition protest march).Logical formLearned from6 sentences. An embargo may prevent a country from exporting petroleum.Logical formLearned from6 sentences. Roadblocks may prevent a female.Logical formLearned from6 sentences. Breweries may prevent beers from gaining (guest status).Logical formLearned from6 sentences. An agreement may prevent outbreaks of violence.Logical formLearned from6 sentences. Sharks may prevent divers from entering water.Logical formLearned from6 sentences. An army may prevent soldiers from looting.Logical formLearned from6 sentences. Resistance may prevent a war.Logical formLearned from6 sentences. Persons may be prevented from votting in an election.Logical formLearned from6 sentences. A victory may prevent golfers from a sweep of some major championships.Logical formLearned from6 sentences. Leadership may prevent safe havens.Logical formLearned from6 sentences. A foam may prevent ice from forming on a tank.Logical formLearned from6 sentences. An operation may succeed in preventing parties.Logical formLearned from6 sentences. A male may prevent convoys from passings.Logical formLearned from6 sentences.