北风“呼呼”地刮着,又一个寒冷的冬天到来了。吃过早饭,龙飞穿着厚厚的羽绒服来到了学校。到了冬天,校园里既看不到鲜花,也看不到小草,连小鸟都不见了踪影。龙飞刚坐到座位上,上课的铃声就响了。接着,三井老师穿着棉衣走进了教室。“我们尽管天天生活在地球上,但对地球内部了解得并不多。今天,我们就来学习一些这方面的知识。”三井老师说,“地球内部是炽热的岩浆,温度可以 North wind ”whirring “ to scratch, another cold winter is coming. Eat breakfast, Longfei wearing a thick jacket came to school. In winter, the campus can not see the flowers, can not see the grass, even the birds are gone. Longfei just sat in the seat, the ring rang class. Then, Mitsui teacher walked into the classroom wearing cotton. ”Although we live on earth every day, we do not know much about the interior of the earth and today we learn some knowledge about it.“ ”Teacher Mitsui said," The earth is hot magma and its temperature can be