Sedimentary rocks—the most common rocktype near the surface—are also the most common reservoirs for water because they contain the most space that can be filled with water.
沉积岩——地表附近最常见的岩石类型——也是最常见的储水层，因为它们可以装水的空间最多。
2
Gem is the most beautiful and expensive rocktype.
宝石是岩石中最美丽而贵重的一类。
3
The deposit belongs to low sulphide altered rocktype.