Exertions can be necessary.Logical formLearned from5 sentences. Assembly can be necessary.Logical formLearned from5 sentences. Encouragement can be necessary.Logical formLearned from5 sentences. (Animal models) can be necessary.Logical formLearned from5 sentences. Aids can be necessary.Logical formLearned from5 sentences. (Bypass surgery) can be necessary.Logical formLearned from5 sentences. Culling can be necessary.Logical formLearned from5 sentences. Scores can be necessary.Logical formLearned from5 sentences. (Reform measures) can be necessary.Logical formLearned from5 sentences. Political change can be necessary.Logical formLearned from5 sentences. A (police presence) can be necessary.Logical formLearned from5 sentences. Investigations can be necessary.Logical formLearned from5 sentences. An evacuation of counties can be necessary.Logical formLearned from5 sentences. A registration can be necessary.Logical formLearned from5 sentences. A memorandum can be necessary.Logical formLearned from5 sentences.