drainage

这块农田需要更好的排水系统以防止积水。

This farmland needs better ___drainage to prevent waterlogging.

手术后，医生需要定期进行伤口引流。

After the surgery, the doctor needed to perform regular ___drainage of the wound.

农田的排水系统需要定期清理以防止积水。

The ___drainage system in the field needs regular cleaning to prevent waterlogging.