下面短文中共有10处语言错误，每句中最多有两处。错误涉及一个单词的增加、删除或修改。

1.增加：在缺词处加一个漏字符号∧，并在其下面写出该加的词；2.删除：把多余的词用斜线（\）划掉；3.修改：在错误处下划线，然后把正确的词写在下面；

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。

Ms Smith,

I am secretary of the City Student Union. We were organizing a art exhibition for high school students in the city. It will held on the 9^th of July in the Exhibition Hall of Beihai. More than 1,000 painting will be on show, but high school students and teachers from all the eight districts will come to the event. As you are very popularly with us Chinese high school students, we’d like to invite for you to the exhibition. We would be grateful when you could join them that day.

Looking forward to hear from you soon.

Li Ming

（9分）北京奥运会的开闭幕式给我们留下了深刻的印象。在闭幕式演出中出现了一种新型弹跳鞋叫弹跳跷，主要是由后面的弹簧(弓)和铝件组成。绑在脚上，能够一步行走二到三米的距离，弹跳高度达到一至两米，是青年中新兴的一种体育运动。一名质量m=60kg的学生穿着这种鞋从距地面H=1.8m高处由静止落下，与水平地面撞击后反弹上升的最大高度h=1.25m。忽略空气阻力，取重力加速度g=10m/s²，求：

⑴学生与地面撞击过程中损失的机械能；

⑵学生与地面撞击过程中速度改变量的大小和方向。