题目

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。     Dear Mr. Black, I’m Li Hua, an exchange student from China. I had been studying in your school for a year. I am deep moved by the kindness of people around. What I want to say first is that the teachers here are very friendly. They do what they can help me and encourage me to study hard. Whenever asking, they give satisfactory answers. Beside, my classmates如图所示，质量为0.3ｋｇ的小车静止在光滑轨道上，在它的下面挂一个质量为0.1ｋｇ的小球Ｂ，车旁有一支架被固定在轨道上，支架上Ｏ点悬挂一个质量仍为0.1ｋｇ的小球Ａ，两球的球心至悬挂点的距离均为0.2ｍ．当两球静止时刚好相切，两球心位于同一水平线上，两条悬线竖直并相互平行．若将Ａ球向左拉到图中的虚线所示的位置后从静止释放，与Ｂ球发生碰撞，如果碰撞过程中无机械能损失，求碰撞后Ｂ球上升的最大高度和小车所能获得的最大速度．