The most common amenity in all dorms is what?
select t1.amenity_name from dorm_amenity as t1 join has_amenity as t2 on t1.amenid = t2.amenid group by t2.amenid order by count ( * ) desc limit 1
what's Roof dorm id?
select dormid from has_amenity where amenid = ( select t1.amenid from dorm_amenity as t1 join has_amenity as t2 on t1.amenid = t2.amenid group by t2.amenid order by count ( * ) desc limit 1 )
what is TV Lounge amenity id?
select t1.amenid from dorm_amenity as t1 where t1.amenity_name = 'TV Lounge'