safe interval period安全间隔期
safe falling period安全下降周期
safe crop period安全收割期;安全施药间隔期
safe growth period安全生育期时间
safe period contraception安全期避孕
safe period for use安全使用期
safe full heading period安全齐穗期
The Safe Period安全期
Safe period test安全期测试
N(名词) the period during the menstrual cycle when conception is considered least likely to occur 安全期 [非正式] → see also rhythm method