in vain
01
徒劳, 没有成功
without success or achieving the desired result
例子
Despite hours of searching, the lost keys were found in vain, and she had to get a spare set.
尽管搜索了几个小时，丢失的钥匙还是徒劳地找到了，她不得不拿一套备用的。
He tried to convince them to change their decision, but his efforts were in vain, and the plan proceeded as initially intended.
他试图说服他们改变决定，但他的努力徒劳，计划还是按最初的意图进行了。
