the onset of winter meaning in Chinese

冬天的突然降临

Cold hardening ( cold acclimation ) processes taking place in plants before the onset of winter that prepare them to withstand low temperatures
低温锻炼（低温驯化）：在冬季来临之前植物体内发生的一些生理变化，目的是为了经受即将来临的低温。
In both evergreen and deciduous trees old leaves are continually shed throughout the growing season , but the remaining leaves are also shed at the onset of winter or a dry season in deciduous species
在植物整个生长季内，常绿植物和落叶树的老叶不断脱落，落叶植物残留的叶在冬季或干季也会脱落。
For years , the situation in afghanistan has been very difficult . the country s crisis is the result of years of war and severe drought . this year , with the onset of winter , conditions are expected to worsen
阿富汗多年来一直处于非常艰苦的困境，而此危机则肇因于长年的战乱与严重的旱灾，今年随着寒冬的来临，情况恐怕更是雪上加霜。