Contests can be arduous.Logical formLearned from2 sentences. Turns can be arduous.Logical formLearned from2 sentences. A bone-marrow can be arduous.Logical formLearned from2 sentences. (Mountain stages) can be arduous.Logical formLearned from2 sentences. (Bone marrow transplants) can be arduous.Logical formLearned from2 sentences. Monologues can be arduous.Logical formLearned from2 sentences. A (repair work) can be arduous.Logical formLearned from2 sentences. A spacewalk can be arduous.Logical formLearned from2 sentences. Walkings can be arduous.Logical formLearned from2 sentences. A (mule ride) can be arduous.Logical formLearned from2 sentences. Searchings can be arduous.Logical formLearned from2 sentences. A digging can be arduous.Logical formLearned from2 sentences. A (pilot training) can be arduous.Logical formLearned from2 sentences. Negotiations may prove arduous.Logical formLearned from2 sentences. Talks can be arduous.Logical formLearned from2 sentences.