blind alley

名词 blind alley:

1. a street with only one way in or out
   同义词：cul de sac, dead-end street, impasse
2. (figurative) a course of action that is unproductive and offers no hope of improvement

1. We tried one idea after the other, but they all seemed to be leading to blind alleys.
   我们想了一个又一个主意，但它们似乎都行不通。