Bright ejecta rays such as these are produced as impacts excavate and eject relatively unweathered subsurface material.

这些放射状陨石坑产生于天体撞击溅出的下物质，绵延在遍布陨石坑的星面数百公里。

In light of the hazards and uncertainties associated with subsurface waste disposal, deep well injection may create pollutional problems.

由于下废处置的危险性和不可靠性，深井注入也会产生污染。

The karst depression belongs to the accumulative area of surface water and subdrainage area of subsurface water, the karstification is relatively week, and reservoirs are undeveloped.

岩溶斜坡和岩溶洼为汇集区及下泄区，岩溶作用相对较弱，储层不发育。