材料一：“黄河流失的不是泥沙，而是中华民族的血液。平均每年泥沙流失量高达16亿吨，这不是微血管破裂，而是主动脉出血。”

黄河是母亲河，孕育了中华民族的古老文明……长江流域同黄河流域一样，是我国古代文明发祥地之一。长期以来，严重的水土流失困扰着长江，使长江染上了两大重病：面呈黄色——富含泥沙；性情暴躁——洪水泛滥。同黄河流域一样，植被的严重破坏是长江流域水土流失的根本原因。

——《母亲河，你带走的是什么？》

材料二：中国文明是世界最古老的几个文明之一。同古代埃及、古代两河流域和古代印度文明一样，我国……发生的文明也是大河流域的农业文明。它们共同对人类文明作出了奠基性的贡献。

——《世界历史》

C

    Do you have brown hair? Are you taller than other kids your age? These characteristics were decided before you were born. You got your traits from your parents. They passed their traits on to you through genes (基因).

    Genes carry codes (代码) for blue eyes or brown eyes. Genes say how tall you will get and what color hair you will have. You got half of your genes from your mother. You got half of your genes from your father. So you have your own set of genes. Each person gets different genes for each body part. That is why you look like but not exactly like your brother or sister.

    A dominant (显性的)  gene shows up most of the time. Brown eyes are dominant over bluc eyes. A recessive (降性的)  gene shows up less often. Light hair comes from a recessive gene. Dark hair is more common. Look at the eye color and hair color of the people around you. You will see that this is true.

    Genes help to make you who you are. But they don't tell the whole story. Your genes may help you to be fast and strong. But you still need to learn how to run or swim or skate well.

“南朝四百八十寺，多少楼台烟雨中”，诗句中的“南朝”四个朝代的先后顺序依次为（    ）