adv.徒劳地，不成功地，白费力地

He searched vainly for his lost keys in the darkness.
他在黑暗中徒劳地寻找丢失的钥匙。
She tried vainly to hide her disappointment when she didn't get the job.
当她没有得到那份工作时，她试图掩饰自己的失望，但没有成功。
The little boy cried vainly for his mother's attention, but she was too busy on the phone.
小男孩徒劳地哭着想引起妈妈的注意，但她正忙于打电话，无暇顾及。
The athlete trained tirelessly, but vainly, as he failed to qualify for the finals.
这位运动员不懈地训练，但最终还是徒劳无功，未能晋级决赛。
He argued vainly with the traffic officer about the unfairness of the ticket.
他徒劳地与交通警察争论罚单的不公。
She searched the bookstore vainly for that rare edition novel she had been渴望拥有很久了。
她在书店里徒劳地寻找那本她渴望已久的稀有版本小说。
The opposition party protested vainly against the new tax law, but it was already passed.
反对党徒劳地抗议新税法，但它已经通过了。
He struck the door vainly, hoping someone would hear and let him in, but the house was empty.
他徒劳地敲打着门，希望有人能听见并让他进去，但房子里空无一人。
She defended herself vainly against the false accusations, unable to clear her name.
她徒劳地为自己辩护，针对那些不实的指控，却无法洗清自己的名声。
The gardener watered the dried-up plant vainly, hoping for a miraculous recovery, but it was too late.
园丁徒劳地给枯萎的植物浇水，希望能奇迹般地复苏，但为时已晚。