Table: betten_bettmeralp_tramway
Columns: name_or_route
type
elevation_groundstation
elevation_mountainstation
slope_length
capacity_in_persons_hour
construction_year_s

Question: Which elevation groundstation has a capacity in persons/hour larger than 820, and a Name or route of lager 1, and a slope length smaller than 336?
SQL: SELECT AVG("elevation_groundstation") FROM betten_bettmeralp_tramway WHERE "capacity_in_persons_hour" > 820 AND "name_or_route" = 'lager 1' AND "slope_length" < 336

Question: Which slope length has a type of surface lift, and an elevation groundstation smaller than 1974, and a construction year(s) of 1971, and a Name or route of alpmatten 1?
SQL: SELECT "slope_length" FROM betten_bettmeralp_tramway WHERE "type" = 'surface lift' AND "elevation_groundstation" < 1974 AND "construction_year_s" = '1971' AND "name_or_route" = 'alpmatten 1'