Persons may go through difficulties.Logical formLearned from11 sentences. A difficulty may lead to a law.Logical formLearned from11 sentences. A sense can be constituted-of-or-filled-with difficulty.Logical formLearned from11 sentences. A difficulty can be for a military.Logical formLearned from11 sentences. Difficulties of conducting a survey of (voter opinion) may introduce sources of error.Logical formLearned from11 sentences. The economy may experience difficulties.Logical formLearned from11 sentences. Some persons may have a difficulty.Logical formLearned from11 sentences. Difficulty can be in achieving orgasm.Logical formLearned from11 sentences. Difficulties may multiply.Logical formLearned from11 sentences. Difficulties can be a factor.Logical formLearned from11 sentences. Difficulties may cast ballots.Logical formLearned from11 sentences. Difficulty can be in behavior.Logical formLearned from11 sentences. A person may have (difficulty sleepings).Logical formLearned from11 sentences. (Animal models) may have difficulties.Logical formLearned from11 sentences. A degree of difficulty may increase.Logical formLearned from11 sentences.