Challenges can be exciting.Logical formLearned from426 sentences. Challenges can be regulatory.Logical formLearned from422 sentences. An array can be constituted-of-or-filled-with challenges.Logical formLearned from420 sentences. A challenge can be on a male.Logical formLearned from419 sentences. A person may face challenges.Logical formLearned from418 sentences. A person may love a challenge.Logical formLearned from409 sentences. A challenge can be for a country.Logical formLearned from408 sentences. A challenge can be technological.Logical formLearned from408 sentences. Persons may meet challenges.Logical formLearned from398 sentences. Challenges may lie.Logical formLearned from390 sentences. Response can be to a challenge.Logical formLearned from385 sentences. A challenge can be for a country.Logical formLearned from383 sentences. A challenge can be daily.Logical formLearned from381 sentences. A challenge may pertain-to a career.Logical formLearned from378 sentences. Challenges can be daunting.Logical formLearned from374 sentences.