Contributions can be voluntary.Logical formLearned from12 sentences. A contribution can be to engineering.Logical formLearned from12 sentences. A contribution may pertain-to members.Logical formLearned from12 sentences. A contribution can be to (country music).Logical formLearned from12 sentences. Contributions can be to technologies.Logical formLearned from12 sentences. A contribution can be to a campus.Logical formLearned from12 sentences. A contribution can be a discovery.Logical formLearned from12 sentences. Contributions can be to theoretical physics.Logical formLearned from12 sentences. Alumni may make contributions.Logical formLearned from12 sentences. Contributions can be to (jazz music).Logical formLearned from12 sentences. (Employer contributions) can be compulsory.Logical formLearned from12 sentences. Contributions can be to optics.Logical formLearned from12 sentences. A contribution can be to botany.Logical formLearned from12 sentences. A contribution can be to a solution of a problem.Logical formLearned from12 sentences. A contribution can be to a promotion.Logical formLearned from12 sentences.