A us-state may release stiff upper lip.Logical formLearned from2 sentences. A vessel can be stiff.Logical formLearned from2 sentences. Wings may be held stiff.Logical formLearned from2 sentences. Spines can be stiff.Logical formLearned from2 sentences. A (wing action) can be stiff.Logical formLearned from2 sentences. (Plastic boots) can be stiff.Logical formLearned from2 sentences. A paper can be stiff.Logical formLearned from2 sentences. A documentary can be stiff.Logical formLearned from2 sentences. A background can be stiff.Logical formLearned from2 sentences. A membrane can be stiff.Logical formLearned from2 sentences. (Shirt collars) can be stiff.Logical formLearned from2 sentences. A cartridge can be stiff.Logical formLearned from2 sentences. A spacesuit can be stiff.Logical formLearned from2 sentences. A fibre can be stiff.Logical formLearned from2 sentences. Hats can be stiff.Logical formLearned from2 sentences.