1·Beneath this active layer is a second layer called "permafrost", which is frozen all year around, and is impermeable to water.
在这一活跃层下面，是被称为“多年冻土”的第二层，终年冻结，不透水。
2·Russia, however, expects to profit handsomely: its steppes, freed of permafrost, will soon host vast olive groves; a series of pipelines will send extra-virgin supplies westwards.
而俄罗斯期望获取可观的利润：其多年冻土释放后的干草原，将很快布满大量的橄榄树；一系列的管道将把特级初榨橄榄油向西输送。
3·Permafrost is defined as any ground that has stayed below freezing for more that two consecutive summers.
多年冻土是指任何连续两个夏天处于冰点以下的地面。
4·Permafrost Photo: Dentren at en.wikipedia / cc – by – sa 3.0
多年冻土图片：Dentren at en.wikipedia / cc – by – sa 3.0
5·In this thesis, the author systemically study on the asphalt pavement design technology of the permafrost area from the material and the structure.
本文从路面材料和结构两方面，对多年冻土地区沥青路面设计技术进行系统深入的研究。