They changed soil causing nutrients to wash into the ocean creating enormous amounts of algae which sucked up oxygen.

它们改变了土壤结构，导致营养物质被冲进海洋，从而产生了大量的藻类，而这些藻类又吸收了氧气。

Here and there a live oak told of changing soil.

到处都有一棵活橡树诉说着土壤的变化。

He descended from the town level by a steep road in a north-westerly direction, and continued to move downwards till the soil changed from its white dryness to a tough brown clay.

他沿着西北方向的一条陡峭道路从镇上下来， 继续向下移动， 直到土壤从白色干燥变成坚硬的棕色粘土。