My name is Sam. I am a junior high school student. My school is close to my home, so I always go to school on foot. Classes start at 8 a.m., and I am seldom late. I like Geography best. I enjoy learning about different places in the world.

    In the morning, we usually study Chinese, Maths and English. We have our morning break at 9:50 a.m..  When the bell rings, I run to the playground with my best friends Tom and Jack. We often play games. Break ends at 10:10 a.m..

Lunch is from 11:50 a.m. to 12:30 p.m.. Afternoon classes end at 3:30 p.m. Then Tom, Jack and I take part in the school bank practice. We make great music together.

    I always have a good time at school.

如图所示，O是直线AB上一点， 图中小于180°的角共有（　　）

19世纪初期，当蒸汽机车轰鸣奔驰的时候……保守人士惊呼，铁路会带来某种“平等化的危险”。民主人士拍手称快：“我看到火车真高兴，我想封建制度是永远一去不返了。”这段材料主要反映了先进科技

如图，在矩形ABCD中，对角线AC，BD相交于点O，E是边AD的中点．若AC=10，DC=$2\sqrt{5}$，则BO=____ ，∠EBD的大小约为　____ 度____ 分．（参考数据：tan26°34′≈$\frac{1}{2}$）