Chinese people nee getting accustomed to using credit cards，but not yet to personal checks，which have long been popular in the Western countries：

—— do you clean your classroom ——0nee a day．

A:How manv B:How long C:How often D:How much

—— do you clean your classroom ——0nee a day．

A:How manv B:How long C:How often D:How much

—— do you clean your classroom ——0nee a day．

A:How manv B:How long C:How often D:How much

—— do you clean your classroom ——0nee a day．

A:How manv B:How long C:How often D:How much