A contribution can be challenging.Logical formLearned from6 sentences. A documentary can be challenging.Logical formLearned from6 sentences. A regulation can be challenging.Logical formLearned from6 sentences. A rhetoric can be challenging.Logical formLearned from6 sentences. A gap can be challenging.Logical formLearned from6 sentences. A crime can be challenging.Logical formLearned from6 sentences. A (mainstream marketplace) can be challenging.Logical formLearned from6 sentences. Gridirons can be challenging.Logical formLearned from6 sentences. A mood can be challenging.Logical formLearned from6 sentences. (Work conditions) can be challenging.Logical formLearned from6 sentences. A rival can be challenging.Logical formLearned from6 sentences. Operas can be challenging.Logical formLearned from6 sentences. A competitor can be challenging.Logical formLearned from6 sentences. A price can be challenging.Logical formLearned from6 sentences. A (dance style) can be challenging.Logical formLearned from6 sentences.