This is my beautiful home. There is a small garden in front of my house. There are many beautiful flowers in the garden. Behind my house there is a big tree. Near the tree, you can see a garage. My father’s beautiful car is in it now.
   On the first floor, there is a large living room, a dining room, a kitchen and a bathroom. I like watching TV in the living room. On the second floor, there is a small study room and two bedrooms. I love playing with the computer in my study. 
   What a nice home! I like it very much.

材料一：1929年12月，在北京房山周口店龙骨山，我国考古工作者发现了北京人的第一个头盖骨化石，后来又发现了5个比较完整的头盖骨化石和200多块骨化石，还有大量的打制石器、动物化石和灰烬。

材料二：北京人生活的时代，周口店一带林草茂密，猛兽经常出没……由于生活环境险恶……北京人往往几十个人生活在一起，共同采集、共同狩猎……过着群居生活。这是人类最原始的社会组织形式。