下列关于位移和路程的说法，正确的是（   ）

读《宿新市徐公店》完成练习。

宿新市徐公店

篱落疏疏一径深，

树头花落未成阴。

儿童急走追黄蝶，

飞入菜花无处寻。

短文改错：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。
    It was 7:15 in the morning of February 8, 2007. I was walking along Park Road towards the east while an old man came out of the park on the other sides of the street. Then I saw a yellow car drive up Third Street and made a right turn into Park Road. The next moment the car hit the man while she was crossing the road. He fell with a cry. The car didn't stop and drive off at full speed heading west. I noticed the driver was young woman wore a pair of glasses and the plate number was AC864. After two minutes later, I stopped a passed car and took the old man to the nearest hospital.

计算：

将2 mol SO₂, 1 mol O₂充入带活塞的密闭容器中，发生反应2SO₂(g)+ O₂(g) 2 SO₃(g),达到平衡后，改变下列条件，SO₃的平衡浓度不改变的是