Table: adler
Columns: name
design
manufacturer
acquired
disposed

Question: What is the average year for Wallenstein with 1a1 design?
SQL: SELECT AVG("acquired") FROM adler WHERE "design" = '1a1' AND "name" = 'wallenstein'

Question: What design was acquired in 1875?
SQL: SELECT "design" FROM adler WHERE "acquired" = 1875