Question

retroactive adj.反动的;追溯的;有追溯力的;从以往某天开始生效; adv:retroactively~

Accepted Answer

英[ˌretrəʊˈæktɪv]  美[ˌretroʊˈæktɪv] ADJ（决定或行为）有追溯效力的If a decision or action is retroactive, it is intended to take effect from a date in the past.例：There are few precedents for this sort of retroactive legislation.这种有追溯力的法规鲜有先例。

单词	retroactive
音标	英[ˌretrəʊˈæktɪv] 美[ˌretroʊˈæktɪv]
解释	adj.反动的;追溯的;有追溯力的;从以往某天开始生效;
例句	ADJ （决定或行为）有追溯效力的 If a decision or action is retroactive, it is intended to take effect from a date in the past. 例：There are few precedents for this sort of retroactive legislation.这种有追溯力的法规鲜有先例。
变形	adv:retroactively~

Retroactive 英[ˌretrəʊˈæktɪv 美[ˌretroʊˈæktɪv Adj.反动的;追溯的;有追溯力的;从以往某天开始生效 Adj 决定或行为）有追溯效力的 Decision Action