The 2007 versions of these products were slightly longer (apparently mostly attributed to longer tobacco rods), and had slightly higher packingdensity, but slightly lower moisture content.
2007年版的产品略长(显然主要因为烟杆较长)填充密度较高，不过，水分含量略低。
2
This high packingdensity accounts for the strength and stability of cement, which makes it useful for structures like tunnels and Bridges.
这种高堆积密度说明了水泥的高强度和稳定特性，使其成为隧道和桥梁等建筑物的理想材料。
3
High packingdensity greatly impedes the cooling of the array.