1.phase in:V.to intriduce something in stages or gradually
逐步采用或实施
The government is going to phase in the new pension scheme over five years,
政府将在五年内逐步实施新的退休金计划.
2.phase out v.to stop or remove something in stages or gradually
逐步结束或淘汰
The bus service to country areas is being phased out
通往农村的公共汽车服务正在被逐步取消.
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