如果使用得当，避孕套是很有效的避孕手段。Condoms are an effective method of birth control if used with care.服用避孕药是最有效的避孕方法。The pill is the most efficient method of birth control.记下信用卡卡号，核对有效期限。Make a note of credit card numbers and check exp...

“有效”的拼音为：yǒu xiào...

“有效”的反义词：无效, 失效。...

“有效”的近义词/同义词：有用。...

“有效”的英语可以翻译为：effective，valid，efficacious，availability，be good for ...