1·This means topsoil contains few of the ingredients needed for long-term successful farming.
这意味着表层土壤几只含有少量长期成功耕作所必需的成分。
2·Because of this increased concentration, regrowth of plants is minimal, leading to increased erosion, which leads to a decrease in the fertile topsoil, leading to even less regrowth.
由于浓度的增加，植物的再生长很少，导致侵蚀增加，使得肥沃的表层土壤减少，再生长更少。
3·Calm and peaceful for most of the year, the Nile used to flood annually, thereby creating, irrigating and carrying new topsoil to the nearby farmland on which ancient Egypt depended for livelihood.
尼罗河虽然在一年的大部分时间里平静而祥和，但是过去每年都会泛滥，从而生成、灌溉并把新的表层土搬运到附近的古埃及人赖以为生的农田。
4·As it crashed down the steep mountainside like a gigantic snowplough, it swept up trees, boulders and tons of topsoil, and completely crushed and destroyed the six villages that lay in its path.
它像一台巨大的扫雪机一样冲下陡峭的山坡，卷走了树木、巨石和成吨的表土，将沿途的六个村庄彻底摧毁。
5·Calm and peaceful for most of the year, the Nile used to flood annually, thereby creating, irrigating and carrying new topsoil to the nearby farmland, on which ancient Egypt depended for livelihood.
尼罗河在一年的大部分时间里平静而祥和，过去每年都会泛滥，从而创造，灌溉并把新的表土运到附近的农田，古埃及赖以生存。
6·Water sank rapidly through topsoil.
水很快地渗透了表土。
7·The topsoil has been almost completely washed away.
表层土壤已差不多完全给冲走了。
8·When it rains hard, landslides sweep topsoil down to the sea.
下大雨的时候，山崩会把表层泥土席卷到海里。
9·And because it washes away rich topsoil, erosion can threaten crop yields.
并且由于丰富的表层土被冲刷掉，土地侵蚀威胁到农作物产量。
10·Villagers may be persuaded to build terraces to stop topsoil running off.
村民会被劝说建造更多的梯田好让表层土不被冲刷掉。