adj.不成功的，失败的，落空的

The project was an unsuccessful attempt to revive the struggling company.
这个项目是挽救这家陷入困境的公司的尝试，但以失败告终。
His bid for the presidency was unsuccessful, receiving very few votes.
他竞选总统的努力没有成功，获得的选票寥寥无几。
She applied for ten jobs but was unsuccessful in securing any.
她申请了十份工作，但都未能如愿得到录用。
The experiment was an unsuccessful one, as it yielded no significant results.
这次实验结果令人失望，因为没有得出任何重要发现。
His business venture turned out to be an unsuccessful endeavor.
他的商业计划最终证明是一次失败的尝试。
The surgery was unsuccessful and resulted in further complications.
手术没有达到预期效果，反而引发了更多的并发症。
Despite her best efforts, she failed to pass the driving test, making it an unsuccessful attempt.
尽管她尽了最大努力，但驾驶考试还是没通过，这是一次失败的尝试。
The减肥计划对她来说是不成功的，体重反而增加了。
The negotiation between the two parties ended up being an unsuccessful meeting.
双方的谈判最后以失败告终，没有达成任何协议。
The new software update proved to be an unsuccessful fix for the system issues.
新软件更新未能成功解决系统问题，反而引入了新的故障。