{"document":{"title":"na","text":"Users who download a free sample issue of Science Digital are agreeing that they may receive occasional e-mail messages from AAAS in exchange for this free content. Users who do not wish to receive e-mail may follow the unsubscribe instructions at the bottom of any e-mail message from AAAS. ","paragraphs":null,"sentences":null,"tokens":null,"language":null},"classifications":[{"level":"document-Union","labels":["User Choice/Control","Practice not covered"],"label_definitions":null}]}