up to a specified time 直到某一时刻
Specified time period 在规定的时间段内
non-specified-time relay [电] 非定时限继电器
consolidation within a specified time 限期整顿
specified time interval 特定时间间隔 ; 释义特定时间间隔
a specified time 一段限定的时间
The Specified Time 指定时间
But it's only an effective vaccine in the context where you have people who can go to the doctor's office, or to an urgent care, some kind of medical facility, three times, reliably, at a specified period of time.
但为了保证接种效果,人们必须亲自去诊疗室,或者在急诊室里,使用一些医学设施辅助接种,还需要接种三次,它只在一段时间内有效
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