A country may tighten (airline safety procedures).Logical formLearned from5 sentences. Troops may tighten security.Logical formLearned from5 sentences. A US-president may tighten an embargo.Logical formLearned from5 sentences. A country may tighten (immigration laws).Logical formLearned from5 sentences. A country may tighten (security checks).Logical formLearned from5 sentences. Some states may tighten security.Logical formLearned from5 sentences. Shoppers may tighten belts.Logical formLearned from5 sentences. Closures may be tightened over (holiday periods).Logical formLearned from5 sentences. Persons may tighten checkpoints.Logical formLearned from5 sentences. A team may tighten financial controls.Logical formLearned from5 sentences. A noose may tighten at a time.Logical formLearned from5 sentences. A country may tighten (visa regulations).Logical formLearned from5 sentences. A disease may tighten a grip.Logical formLearned from5 sentences. A country may tighten (export laws).Logical formLearned from5 sentences. A country may tighten procedures.Logical formLearned from5 sentences.