at the top of the dunes, and it won't last long. 难以触及 而且不会久留

315. is cooled and blown inland,
     冷却并被吹至内陆
316. forming fog banks that shroud the desert in mist.
     形成雾堤 笼罩沙漠
317. This precious moisture lies tantalisingly out of reach
     这些珍贵的水汽诱人地弥漫在沙丘顶部
318. at the top of the dunes, and it won't last long.
     难以触及 而且不会久留
319. It'll be burnt off by the sun just hours after it rises.
     太阳升起数小时后就会被烤干
320. Darkling beetles race to the top of the dunes
     拟步甲狂奔至沙丘顶部
321. to reach the fog before it vanishes.
     要赶在薄雾消失之前吸收水分

来自《行星地球 第二季 第四集 Planet Earth S02E04 沙漠》第 318 行