perpetualadj.永久的；永恒的；一再往复的perpetual motion machine永动机perpetual yard inventory编组场现在车数,出入车数和停留时间的永久记录单perpetual calendar watch永久日历表perpetual inventory card[经] 永续盘存卡perpetual inventory sheet永续盘存明细表perpetual Bermudan option永久百慕大期权perpetual parthenogenesis永久单性生殖perpetual asphalt pavement长寿命沥青路面perpetual inventory method持续盘存法perpetual inventory system永续盘存制

1. The weight of snow collapsed the roof.
   积雪的重压使屋顶倒塌了。
2. A heavy lorry floundered about in deep snow.
   一辆重型卡车在厚厚的积雪中艰难地行进。