fruitless
adj. 不成功的，徒劳的；不结果实的
例句
After a fruitless morning sitting at his desk he had given up.
他在书桌前徒劳地坐了一个上午后便放弃了。
《柯林斯英汉双解大词典》
He stopped to watch his son's fruitless efforts.
他停下来看儿子徒劳的努力。
It was a fruitless search.
那是一次毫无结果的搜寻。
