出单双出现规律的公式百度一下简介：After all the hard work of cleaning the dormitory, Su Can put the mop on the balcony railing to dry, took a deep breath and said: Finally, the cleaning is done.
After all the hard work of cleaning the dormitory, Su Can put the mop on the balcony railing to dry, took a deep breath and said: Finally, the cleaning is done.
