A crust can be tough.Logical formLearned from13 sentences. Campaigns can be tough.Logical formLearned from13 sentences. A rap can be tough.Logical formLearned from13 sentences. An enclosure can be tough.Logical formLearned from13 sentences. A male can be tough on a female.Logical formLearned from13 sentences. A quest can be tough.Logical formLearned from13 sentences. A car can be tough.Logical formLearned from13 sentences. A day can be tough.Logical formLearned from13 sentences. A homestand can be tough.Logical formLearned from13 sentences. (Muscle building) can be tough.Logical formLearned from13 sentences. Nights can be tough.Logical formLearned from13 sentences. A yard can be tough.Logical formLearned from13 sentences. Orders can be tough.Logical formLearned from13 sentences. A tough loss can be to a us-state.Logical formLearned from13 sentences. A (bargaining position) can be tough.Logical formLearned from13 sentences.