But it was clear that they were not pumping clean sand for a family beach.

但很明显，他们不是在为家庭海滩抽干净的沙子。

When they have all been placed,   a dredger begins pumping sand into what will become the interior of the  island, until around half of it is filled.

当它们都被放置好后，挖泥船开始将沙子泵入将成为岛内部的地方，直到大约一半被填满。