在2014年底，我国不少省市ETC联网正式启动运行，ETC是电子不停车收费系统的简称．汽车分别通过ETC通道和人工收费通道的流程如图所示．假设汽车以正常行驶速度v₁=16m/s朝收费站沿直线行驶，如果过ETC通道，需要在距收费站中心线前d=8m处正好匀减速至v₂=4m/s，匀速通过中心线后，再匀加速至v₁正常行驶；如果过人工收费通道，需要恰好在中心线处匀减速至零，经过t₀=25s缴费成功后，再启动汽车匀加速至v₁正常行驶．设汽车在减速和加速过程中的加速度大小分别为a₁=2m/s²，和a₂=1m/s²．求：

体温计示数升高时，关于体温计内的水银，下列物理量不变的是（　　）

下列各句中，没有语病的一句是     (　　)

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。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。

    I had an amazing experience last Spring Festival. On the second day of the holiday, it was snowing heavily but we had a very importance relative to visit, that lived in a distant mountain village. We have to take risks to drive on our journey. Though the road was bad, but we arrived safe.

    The family welcomed us warmly or we said “ Happy new year" to them. We were treated a good dinner. Later in the afternoon, we said goodbye and started back home. Sadly, our car sticking in the snow halfway and wouldn't move. Just then, the villager walked by, offering to push his car. It was this stranger who helped us out!