Read and choose. （阅读理解，选择合适的选项）

     Welcome to my school. There are 30 classrooms in my school. Look, this is a big playground.

In this building (大楼), you can see the gym,  the library and the art room.  They are on the first floor.

There are many story-books and picture books in the library. You can read books in it.  My

classroom is on the second floor.  It's big and clean.  I like it.

1. There are _____ classrooms in my school.            

A. thirty            

B. thirteen

2. The playground is _____.           

A. small            

B. big

3. The library is on the _____ floor.          

A. first            

B. second

4. My classroom is _____.           

A. clean            

B. small

5. I _____ my school.             

A. don't like      

B. like

（1）在“研究匀变速直线运动”的实验中：小车拖着纸带的运动情况如图所示，图中A、B、C、D、E为相邻的记数点，相邻的记数点的时间间隔是0.10s，标出的数据单位是cm，则打点计时器在打C点时小车的瞬时速度是______m/s，小车运动的加速度______m/s²．

（2）如图所示为频闪摄影方法拍摄的研究物体做平抛运动规律的照片，图中A、B、C为三个同时由同一点出发的小球．AA′为A球在光滑水平面上以速度v运动的轨迹；BB′为B球以速度v被水平抛出后的运动轨迹；CC′为C球自由下落的运动轨迹．通过分析上述三条轨迹可得出结论：______．