实验题。

一项“过关游戏”规定：在过第n关时要将一颗质地均匀的骰子（六个面上分别刻有1到6的点数）抛掷n次，若n次抛掷所出现的点数之和大于n²，则算过关；否则不算过关，则能过第二关的概率是（　　）

增加：在缺词处加一个漏字符号（∧）,并在其下面写出该加的词。

删除：把多余的词用斜线（＼）划掉。

修改：在错的词下划一横线,并在该词下面写出修改后的词。

注意：1）每处错误及其修改均限一词;

2）只允许修改10处,多者（从第11处起）不计分。

    I will share one experience with you. With the College Entrance Examination draw near, I was filled with great anxiety. However, I couldn't be absorbed in study, resulting my failing in the examination. I got very discouraging. Just then, my teacher, Miss Zhang, approach me and said, "In life we all have moment when we can't achieve what we want it. It is natural. Don't allow those moments to weak you, but turn them into motivation to inspire you." Her words were a reminder which provided myself with constant encouragement to smile at life. Consequently, I gained what I deserved.

    So it is an optimistic attitude which matters most of all. It gives you the confidence to deal with difficulties and to achieve what you want in your life.

下表列出了相同条件下不同物质密度及声音在其中传播的速度，根据表中提供的信息，可以得出的结论是（    ）