假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。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：在错的词下面画一横线，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。

    The other day, some of my classmates and I took a bicycle trip along the "Huan Shan Green Road", that was specially built for people to relax ourselves. The scenery along the road was fascinating, with trees, flowers, hills and lakes on both side. We stopped by a lake for a rest, where a great many of people are playing happily. But something unpleasant caught our eyes. There was rubbish here or there, and there were many plastic bags and bottles floated on the surface of the lake. Such beautiful place was so serious polluted. What a shame! In the end, we couldn't help collecting the rubbish after we left.

如图所示，传送带的倾角θ=37°，在电动机的带动下以v=4m/s的速率沿顺时针方向运行，在传送带的底端B有一离传送带很近的挡板P可将传送带上的物块挡住，在传送带的顶端A无初速地释放一物块，它与传送带间的动摩擦因数μ=0.5，A、B间的长度L=9m，物块与挡板碰撞前后物块的速度大小不变，方向相反，物块与挡板的碰撞时间极短．取g=10m/s²，sin37°=0.6，cos37°=0.8．求：