Contributors may undergo a survey.Logical formLearned from4 sentences. A contributor may pertain-to a material.Logical formLearned from4 sentences. A contributor can be to changes.Logical formLearned from4 sentences. Pollution can be a contributor.Logical formLearned from4 sentences. A contributor can be to some others.Logical formLearned from4 sentences. Contributors can be to a profession.Logical formLearned from4 sentences. A country can be a contributor to a (peacekeeping force).Logical formLearned from4 sentences. Contributors may include experts.Logical formLearned from4 sentences. Contributors can be to an experience.Logical formLearned from4 sentences. A contributor can be to a public good.Logical formLearned from4 sentences. Some contributors may note that something-is-the-case.Logical formLearned from4 sentences. (Sulfur dioxide) can be contributors to (acid rain).Logical formLearned from4 sentences. Contributors can be to a behavior.Logical formLearned from4 sentences. Contributors may fear a disappearance of a rural life.Logical formLearned from4 sentences. Money may come from contributors.Logical formLearned from4 sentences.