dead end

When it comes to transportation, a dead end is a street that has no exit. This expression is also used for something that leads to no progress no success. If the police are investigating a crime and they come to a dead end, it means they do not succeed in solving the crime.

说到交通时，a dead end就是没有出口的道路。同时这个表达也可以用来形容一件没有办法进步或成功的事情。如果警察正在调查一项犯罪，而他们走到了a dead end，这意味着他们没有成功地破案。

Even though your research appears to be at a dead end now, you shouldn't lose heartbut keep on trying.

即使你们的研究现在似乎没有什么进展，你们还是不应该泄气，而要继续进行下去。