徒劳: futile effort; fruitless lab ...无效: of no avail; to no avail; in ...徒劳,白费,无效: in vain徒劳的,无效的: in vain不结果实的;无效的;徒劳的: fruitless徒劳: futile effort; fruitless labour 要想阻止历史潮流是徒劳的。 it is always futile to try to hold back the progress of history无效: of no avail; to no avail; invalid; null and void; nullity (合同等的); in vain; unavailability; ineffectiveness; inefficiency; futility; flop 宣布选举无效 nullify an election; 医治无效 fail to respond to medical treatment; 宣布决定无效 declare decision invalid; 无效的契约 an invalid contract; 无效投资 make the investment inefficient; 无效法律行为 nullity of juristic act; 无效分蘖 [农业] ineffective tillering; 无效功 lost work; 无效合同 invalid contract; 无效劳动 lost labour (in agricultural production); 无效期 adynamic stage; 无效诉讼 annulment suit; 无效条款 irritancy; 无效约因 infirmative consideration白费,徒劳: in vain吠月, 徒劳: bark at the moon; bay the moon徒劳的: cutting it fine; empty; furitless; futile; in vain; infructuous; rewardless; sisyphean; unavailing; ungrateful; vain徒劳地: fruitlessly; in vain; vainly无用, 徒劳: without avail无效的;使无效;无效: null and void爱的徒劳: love's labour's lost; love’s labour’s lost白费气力, 徒劳: to beat the air捕风捉影, 徒劳: run after a shadow福斯徒劳: faustulus干徒劳的事: milk the bull落空;徒劳无功: draw a blank撒网捕风, 徒劳: catch the wind in a net; catch the wind with a net徒劳, 白费力: beat the air徒劳,白费力: in vain; invain徒劳,白辛苦;轻慢: in vain徒劳,虚荣的: vain徒劳的差事: a fool's errand