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To combine multiple sets to study at once, click the “Combine with other sets” link on the specific set’s page. You will then be directed to the “Combine Sets” page. To add the sets you want to combine, click the plus sign next to the set, then select “Export” from the scroll-down menu. To remove them, click the subtract sign. After clicking “Export,” you can copy the terms, and then paste them into a new set.