number of ply

例句：

1. 1. The engineer calculated the number ofplies in the roof to ensure itsstrength.
   工程师计算了屋顶的层数，以确保其强度。
2. 2. The construction crew carefullymeasured the number of plies for thenew floor.
   建筑工人仔细测量了新地板的层数。
3. 3. The designer wanted toadd a layer of insulation toimprove energy efficiency.
   设计师想要增加一层隔热层，以提高能源效率。