How many days are there in a week?一周有多少天.【Me YC】真诚为你解答，不懂追问！你的【10】分满意，是我前进的动力！帮到你请按【选为满意答案按钮】。吼吼！保证正确，采纳吧is,this,old,shirt,an(.)This is an old shirt。