“徒劳地”用英语怎么说

他在书桌前徒劳地坐了一上午之后便放弃了。After a fruitless morning sitting at his desk he had given up.罪犯们徒劳地躲闪着探照灯光。The criminals vainly sought concealment from the searchlight.她又徒劳地拉了一下门以后,再也忍不住了,就放声哭了起来.She made one more vain effort and t...