Question: What Secretary has a Social AO of Lieke de Boer?
SQL: SELECT "Secretary" FROM "2-18128162-4" WHERE "Social AO" = 'Lieke de Boer';

Question: What Social AO has an External CO of Elena Buscher, and a President of Harm van Leeuwen?
SQL: SELECT "Social AO" FROM "2-18128162-4" WHERE "External CO" = 'Elena Buscher' AND "President" = 'Harm van Leeuwen';

Question: What Social AO has an External CO of Simonas Savickas, and an Internal CO of Pieter Kuijsten?
SQL: SELECT "Social AO" FROM "2-18128162-4" WHERE "External CO" = 'Simonas Savickas' AND "Internal CO" = 'Pieter Kuijsten';

Question: What Secretary has an Internal CO of Isabel Voets?
SQL: SELECT "Secretary" FROM "2-18128162-4" WHERE "Internal CO" = 'Isabel Voets';

Question: What Academic AO has a President of Harm van Leeuwen?
SQL: SELECT "Academic AO" FROM "2-18128162-4" WHERE "President" = 'Harm van Leeuwen';

Question: What Social AO has a President of Harm van Leeuwen?
SQL: SELECT "Social AO" FROM "2-18128162-4" WHERE "President" = 'Harm van Leeuwen';