The pass rate of water supply and drainage training for old goblins is not high. It is well known that the pass rate of registered water supply and drainage engineers is low, which is also the reason why the gold content of drainage engineer certificate is so high. The passing rate of annual review is only 15%-30%, which is less than half the level. Although the passing rate of registered water supply and drainage engineers does not directly indicate whether a person has the ability, it also indirectly indicates whether the person really works hard to practice the exam.