movies used to be shown in an open space ,with audience seated on benches.为什么不是seating

movies used to be shown in an open space ,with audience seated on benches.为什么不是seating be used for be used to be used from区别 used to be used to be翻译 I used to be used to be to be used used to be to be used to be used be used to be used to used to be be used to used to／be used to／be used for的区别 be used for doing,be used to do,be used as,be used in,be used to doing,used to be used to与have used to we ( )go to the movies quite often A used to B are used to C were used to理由!