Borders may tighten.Logical formLearned from7 sentences. Conservative forces may tighten a grip on a country.Logical formLearned from7 sentences. A male may tighten monetary policy.Logical formLearned from7 sentences. A government may tighten a cordon.Logical formLearned from7 sentences. Airlines may tighten security on flights.Logical formLearned from7 sentences. Security may be tightened across a city.Logical formLearned from7 sentences. A government may tighten screws.Logical formLearned from7 sentences. A country may tighten curbs.Logical formLearned from7 sentences. A person may tighten a game.Logical formLearned from7 sentences. (Government forces) may tighten a noose.Logical formLearned from7 sentences. Orders may tighten rules on contact.Logical formLearned from7 sentences. Persons may tighten an encirclement of a city.Logical formLearned from7 sentences. A blockade may be tightened.Logical formLearned from7 sentences. (Foreign ministers) may tighten sanctions.Logical formLearned from7 sentences. A world-city may be tightened.Logical formLearned from7 sentences.