| 摘要 |
<p>The weight consists of a plastics tube (4) containing sacks (5) of similar diameter, filled with sand, gravel or other ballast material to hold down plastics sheeting (2) covering a silage pit or stack of other agricultural product. The sacks are placed end-to-end inside the tubes, which are then closed at both ends and laid across the sheeting to hold it down.</p> |
