| 摘要 |
A manhole cover (1) comprising a top (2) and a base (4) which define a space therebetween, and reinforcing walls (8') which extend at least partially between the top (2) and base (4) to define voids (10, 10') within the sodefined space, wherein the reinforcing walls (8'), and hence the so-defined voids (10, 10'), radiate from the centre region of the cover.
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