题目

Every student as well as teachers who _______ to visit the museum ____ asked to be at the school gate on time. A. is; is                              B. are; are                   C. is; are                     D. are; is   答案：D抛掷一枚均匀的硬币2次，请用列表或画树状图的方法抛掷的结果都是反面朝上的概率。