题目

 “抛一枚均匀的硬币，落地后正面朝上”这一事件是（     ）    A．必然事件B．随机事件C．确定事件D．不可能事件 答案：B?Must I finish my homework now? I want to go home. ?No, you ________. You ________ go home now. A. needn't; can B. mustn't; can C. can't; must D. needn't; must