文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。

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仅限一词；

2）只允许修改10处，多者（从第11处起）不计分。

    I couldn't believe my ears when I heard my name calling. I was chosen to play the leading role in Cinderella, that was my dream. As a shy and thin girl, I used to be quite afraid of speaking in the public. But my parents and teachers always encourage me to do so. Now I have changed great. In class, I am often the first one to stand back and answer questions even if I may make some mistakes. No pains, no gains. Now I am always brave enough overcome the difficulty in my heart and have changed in a lively girl. So my experience shows that we should not be afraid of losing face but only in this way can we make progresses.

某中学一张姓同学随一旅游公司外出游玩,在一公园内溺水身亡,该公园门票含保险费1.5元,保值5万元。事后,该同学家人收到公园寄来的5万元,而旅游公司却于事后才给该同学补办保险,要求保险公司作相应赔偿。保险公司依法对事故核定后,拒绝赔偿,后由法院裁决旅游公司独家承担22万元的赔偿费。

结合材料回答:

为了解某校高三学生的视力情况，随机地抽查了该校100名高三学生的视力情况，得到频率分布直方图如下图，由于不慎将部分数据丢失，但知道前4组的频数成等比数列，后6组的频数成等差数列，设最大频率为a，视力在4.6到5.0之间的学生数为b，则a，b的值分别为   (　 　)

正确运用这些方法和策略，就会使我们在学习中游刃有余，____。