Much of the Sahara is underlain by an enormous freshwater aquifer.
撒哈拉绝大部分区域是由底下的 巨大淡水地下蓄水层支撑。
Those sandy layers are capped with watertight clay which would prevent injected seawater seeping upwards to contaminate freshwater aquifers.
英汉双解词典包含3607232条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。