so it's only the tops that are moving. 所以沙丘移动的部分只是顶部

65. In Namibia the winds have built some of the biggest dunes in the world.
    在纳米比亚 风塑造了 一些世界上最大的沙丘
66. Star dunes like these can be 300 metres high.
    这些巨型沙丘高达300多米
67. Grains, swept up the flanks, are blown off the crests of the ridges
    斜坡上吹起的沙粒 在沙丘顶部的边棱处飞扬
68. so it's only the tops that are moving.
    所以沙丘移动的部分只是顶部
69. The main body of these dunes may not have shifted for 5,000 years.
    这些沙丘的主体 可能已有5000多年未曾移动
70. Few rocks can resist the continuous blast of the sand carrying wind.
    岩石很难抵挡风沙持续不断的摧残
71. These outcrops are standing in Egypt's White Desert.
    这些石头如今矗立在埃及的白色沙漠中

来自《行星地球 第一季 第五集 Planet Earth S01E05 沙漠》第 68 行