题目

If you want to borrow a football after school, your student ____ here.   A. has to leave    B. must leave       C. has to be left D. must be left 答案：C16．某种商品包装为一箱6件，如果在其中不慎混入2件不合格产品，质检员从中随机抽出2件，其中恰有1件不合格产品的概率是$\frac{8}{15}$．