Ships can be challenging.Logical formLearned from4 sentences. A wave can be challenging.Logical formLearned from4 sentences. (Living conditions) can be challenging.Logical formLearned from4 sentences. (Practice questions) can be challenging.Logical formLearned from4 sentences. Scores can be challenging.Logical formLearned from4 sentences. Travel can be challenging.Logical formLearned from4 sentences. A blog can be challenging.Logical formLearned from4 sentences. (Business discussions) can be challenging.Logical formLearned from4 sentences. Animals can be challenging.Logical formLearned from4 sentences. Trust can be challenging.Logical formLearned from4 sentences. (Civilization phase) can be challenging.Logical formLearned from4 sentences. A phrase can be challenging.Logical formLearned from4 sentences. A (mortgage market) can be challenging.Logical formLearned from4 sentences. A puzzler can be challenging.Logical formLearned from4 sentences. A possession can be challenging.Logical formLearned from4 sentences.