In this way , researchers can transiently and reversibly control certain events in specific cell types at defined times .

如此，研究人员可以在特定的时刻暂时性或可逆性地控制特定细胞类型的一些事件。

Scientists have struggled for decades to find ways to reversibly and safely block male fertility .

科学家们，为了找寻可安全地阻断雄性生育能力并又可恢复的方法，已经奋斗了数十年。

Economic theory should not be expected to produce universally valid laws that can be used reversibly to explain and predict historic events .

人们不能期望经济理论能够产生普遍有效的规律，可以用来逆向解释或者预测历史事件。