But they will not do so for much longer. 但它们也坚持不了多久

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
72. But they will not do so for much longer.
    但它们也坚持不了多久
73. They're being inexorably chiseled away and turned into more sand.
    它们正被无情地凿碎 变成更多的沙粒
74. Now lumps of heavily eroded rocks have been marooned in a sea of sand.
    现在 这些严重侵蚀的石块 已被放逐在沙海之中
75. These jagged pyramids a hundred metres tall
    这些高达100多米的锯齿般的石锥

来自《行星地球 第一季 第五集 Planet Earth S01E05 沙漠》第 72 行