adj. reactive, responding to stimuli, acting in return

nm. reagent, substance used to detect or measure another substance or to convert one substance into another by chemical reaction (Chemistry)

v. reactivate, make active again, put into action again, restart

(n.) = reactive ; reagent.
Ex: In all of the helping professions there is need for both active and reactive service.
Ex: Since syntheses involve reactions between specific functional groups, it is reasonable to sort reagents by these groups.
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* tira reactiva = dipstick.

(v.) = reactivate [re-activate].
Ex: The collections were dormant during the 2nd World War, were reactivated about 1964 and now consist of about 180,000 samples.
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* reactivar Algo = get back on + track ; put + Nombre + back on track.
* reactivar la economía = revitalise + the economy.