But Egypt has been building an iron barrier, sunk deep into the sandy soil, to thwart this subterranean traffic.

不过，埃及正在建造深入沙土的钢铁屏障，以阻止秘密的地下交通。

youdao

Mulch forms a barrier between the soil and the air. As a result, mulched soil will be cooler in the summertime. And in winter, it may not freeze as deeply as areas without mulch.

盖土形成土壤与空气之间的屏障，其结果是，被覆盖的土壤在夏季会较凉爽，而在冬季，不会让土壤像没有盖土的区域一样冻得那么深。

youdao

Mulch forms a barrier between the soil and the air.

覆盖物在土壤与空气之间形成屏障。

youdao

Mulch forms a barrier between the soil and the air.

VOA: special.2009.06.30

When it does rain in Queensland, soil washes into the Great Barrier Reef, the world's largest barrier reef.

NPR: Pacific Island Cultures Brace for Climate Change

But Egypt has been building an iron barrier, sunk deep into the sandy soil, to thwart this subterranean traffic.

ECONOMIST: Israel and Gaza

"The big barrier as far as bioenergy crops are concerned is a fear of the unknown in terms of soil carbon losses or gains - this is the gap we are trying to fill, " explained lead researcher Niall McNamara.

BBC: Measuring bioenergy crops' carbon footprint credentials